Sechs from Battle Angel Alita: Last Order either fits the trope or is a parody of it. Starting out as a exact replica of the female main character, by volume 5 Sechs, after losing her original android body, has changed to a 1.8-metre-tall thin but muscular male body. This was either done to get more female readers into the series or to poke fun at the lack of attractive male fighters in the manga. Additionally, in volume 10 it's revealed that Sechs has gained a large female fanbase in the solar system, much to his/her annoyance.
Oga Tatsumi from Beelzebub is most definitely this, especially when he goes shirtless. Other male characters include Himekawa (at least when his hair is out of the pompadour), Natsume, Kanzaki, even some of the Pillar Division members count.
If Black Butler's plot and gorgeous art doesn't keep you hooked on the series, the ridiculous amounts of Ho Yay fodder and gorgeous guys will. Special mention goes to Sebastian, who is, without a doubt, extremely badass, has silky shoulder-length black hair, is extremely tall and handsome, constantly wears black, has a somewhat sensual nature. And considering that his human looks are actually derived from Vincent Phantomhive's... Oh!
Creed from Black Cat qualifies for this trope rather nicely. Somehow, his evil plot to take over the world and kill everyone not up to his standards is justified by his sad Dark and Troubled Past involving his abusive mother. He has a rather deep and sexy voice, and many fans have no doubt that he would have no problems doing male-on-male things with Train. He also has an incredible amount of shirtless scenes (even his regular clothes show his chest). He also has a very naked bath scene where he's barely covered by strategic floating clumps of rose petals, in a slow pan from his feet to his head. And when he gets out of it, they pan as low as they can without showing "little Creed."
Berserk: While Miura is more often known for the sexual exploitation of his female characters (often too grotesque extremes) there are still plenty of attractive male characters who are often showcased, making it a Double Standard.
If Guts the raw machismo-kind of attractive, Griffith has the flip side of the appeal being haunting angelic Bishōnen and often creepily effeminate. Regardless Griffith in his human form gains attraction both in universe and out.
Out of the Hawks (aside from Griffith) Judeau is the prettiest, perhaps too much since he sometimes mistaken for female. Also Judeau has a likable personality out of the group, always supporting his friends and his death caused much heart ache since he withheld his feelings for Casca until his dying breath.
Serpico has much of the similar appeal to which Griffith previously had, being thin prettyboy, but has a different demeanor always very calm and polite with his eyes near permanently shut. Compared to his half sister Farnese Serpico is often considered the more attractive of the pair (since Farnese is no Ms. Fanservice).
Ikkaku's shirt goes missing when he unveils his Bankai, Hisagi never wears sleeves and gets nicely roughed up in his fight with Findor Carias, Kensei has several scenes exposing his lovely, muscular chest and arms...the list goes on and on. Hell, even Mayuri had a Shower Scene that showed that he's actually pretty hot under his weird makeup.
Brave10 has a bevy of Bishōnen in scanty clothing but the Mr. Fanservice is Rokuro by a long mile. He's got crowds sighing over his prettyboy looks in canon, wears a Stripperific outfit which includes pairing a crop top with strappy low rise hakama that have ever-deepening hip windows and have been cut from Magic Skirt cloth, and he eventually gets an identical twin in the sequel, mostly so the author can draw them whipping each other's clothes open when they face off in the tournament arc and a bunch of Twincesty splash pages. To the author's apparent surprise, he was voted the most popular character when the magazine it ran in polled its readership.
Yarai in Cage of Eden. To recap: Yarai is tall, blonde, strong and has highly defined muscles and a big chest that make him the physically biggest character in the series. He has many Shirtless Scene and get a double-page where he bath naked.
Minami from Cherry Juice, who has the natural harem, the non-chalant shirtless-ness, and who is not above kissing his bishonen best friend in order to make his sister jealous. His status as this trope is lampshaded within the manga with the opening line:
In Dragon Ball GT, Trunks is an in-universe example with all the women (and Otokosuki) of Capsule Corp. lusting after him as he walks the halls of the company.
Being a series about American football, Eyeshield21 have wonderfully fit athletes working out, shirtless, or just looking attractive all over the place. Special mentions go to Shin, Kakei, Mizumachi, Akaba and Kotaro.
While Fairy Tail obviously primarily caters to its male fans, it has plenty of male characters catering to the female fans as well.
Gray Fullbuster who, in addition to being the Only Sane Man, and having a tragic backstory, owns a very nice body which readers get plenty of chances to ogle, since his obligatory quirk is stripping to his boxers without realizing it. Hiro Mashima does not try to hide that attracting female fans is Gray's job. When the first major arc focused on Gray, he said it was due to the female fans: there weren't enough of them.
Natsu's top attire consists solely of a vest, leaving his abs completely exposed.
Sting is always exposing his midriff. At one point, one of Sting's attacks seemed to accomplish nothing more than blowing a hole in Natsu's clothing just sizable enough for his abs to show through.
Azuma also, despite existing for only one arc, spent half of it shirtless and showing off a delightfully muscular form.
Fate/Zero's Lancer, Diarmuid ua Duibhne, which is an actual power of his thanks to his cursed Beauty Mark (which causes him tons of problems both in the original myth and in the show). The Einzbern Consultation Room short did not let this go un-lampshaded.
Zecchan: Why isn't there an otome game based on Celtic mythology yet?
Food Wars! is an advocate of equal opportunity for both male and female readers get the eye candy they want. The Cast Full of Pretty Boys is, by itself very fanservicey. The award though goes to Isshiki, who spends most of his screentime either in a Naked Apron or a Fundoshi (when he is working in the field), and the artist does not have a problem with shots of his ass and chest. He even sleeps naked.
For those who prefer a more mature gentleman and a little adventure, Senzaemon Nakiri is both well-built and cut (in fact, he has pretty much the same body type as Gin), long white hair and a few facial scars, and strips whenever he is fed something sufficiently tasty.
And for those who like their men "mad, bad and dangerous", Azami looks good in a suit, and positively mouth-watering when training iaido in a gi just open enough to show the sweat running down his chiseled abs.
Almost every single male character in Fruits Basket. Particularly Momiji, Yuki, Ayame and Kyou. The first wears the girl's school uniform (albeit not with a skirt) because "it looks cuter on him", and gets an Imagine Spot dedicated towards showing him aged-up as a Bishōnen. Yuki has soft grey hair and violet eyes, and made for a pretty convincing girl the time he's forced to wear a dress. Ayame is a white hair given quite a few Bishie Sparkle shots. Then there's Kyou, who fits more in the All Girls Want Bad Boys area, with a Hot-Blooded temper and tendency for dere dere moments around Tohru, and an apparent predilection for shirtlessness. The other males get their fair share of moments as well. Tohru lampshades this once, calling the Sohma family a "family of princes". Generally, the series with its preference towards over-the-top romanticism and Dark And Troubled Pasts aims more for making fangirls swoon rather than squeal, but the Sohma family curse's transformative effects lead to so much nudity that it still fits.
The entire main cast of Free!. The main five are routinely featured in their swimwear in merchandise and official art and are the subject of such shameless, over-the-top fanservice that Gou as a character primarily (and arguably only) exists in order to lampshade how physically attractive they all are. Each one even has a distinct personality to draw fangirls in: The Stoic Haruka, Boy Next Door Makoto, Keet Nagisa, Bookworm Rei, and Jerk with a Heart of Gold Rin.
Havoc also gets several loving shots of his nice biceps, and Ling wanders around with his shirt undone.
Hell, in the 2003 anime, Hohenheim (Ed and Al's father) gets in on it, as he gets a brief Shirtless Scene in a flashback that's also strongly implied to be him making love to his wife (it's handled tastefully, of course, and indeed, played up as a bit of a tearjerker). Subverted though, when we see the bits of his body that are rotting.
Sosuke Sagara is definitely the ultimate example for this show, though. He gets the most shirtless scenes, and in general is the one who is used when someone needs to look sexy.
With Fushigi Yuugi, it's probably just easier to narrow down which male cast members aren't catering to some estrogen brigade bait fantasies. Whether your taste runs to Draco in Leather Pants (Nakago, Suboshi), or to gorgeous, gallant royalty (Hotohori), or to Fiery Redheads (Tasuki) or to your basic romantic hunk (Tamahome), there will be at least one ridiculously attractive male character who gets a) gratuitously wet, shirtless or both; and b) a sympathetic Back Story. Hell, even resident monk Chichiri gets in on the fanservice action.
Lockon Stratos both Neil and Lyle, thank you very much, from Mobile Suit Gundam 00. Somehow, both Shin-ichiro Miki and Alex Zahara manage to do wonderful things with Lockon's voice. It's possible that because he fits this trope so wonderfully that so many fangirls forget what happens when his Berserk Button is pressed...
What, ONLY the fangirls? Many 00 fanboys have claimed the Stupid Sexy Lockon meme for themselves, so smitten they are by his sheer badassery as well as his good looks. For some, if you're not gay/bi for Stupid Sexy Lockon, you're not a 00 fanboy — period.
Then again, this trope can probably be used to point out almost every male character in the series, protagonists and antagonists alike. In A.D. 2307, humanity is still at war... but at least they all look good.
In Hakuouki, nearly all of the high ranking members of the Shinsengumi are Bishōnen, with different members hitting all of the standard personality traits associated with this trope. Given the source material for the series, this shouldn't come as a surprise.
Haven't You Heard? I'm Sakamoto: Sakamoto himself, being basically manga's answer to The Most Interesting Man In the World. He's handsome, cut, elegant, kind, helpful, and excels at anything and everything he does as stylishly as possible. He's fawned over by everyIn-Universe female character, and even some of his male classmates can't seem to decide whether they hate him for his popularity or are in love with him themselves.
The entire male cast of Hetalia: Axis Powers. It really says something when even the main character's grandfather has legions of Squee-ing fangirls.
Higurashi: When They Cry: Keiichi. Aside from his various interesting (and quite exploitative) outfits, he gets a now-quite-infamous Guy-on-Guy Is Hot scene between him and Satoshi in the Kira OVA, which is drooled over In-Universe by the female cast. Apparently, his dad is also one in the manga.
Dio Brando, whose charisma and beauty are stated by many of his more loyal subjects to be their reason for following him. His outfits are usually designed to show off his muscular body (and that's not even counting the scenes where he's shirtless or just straight up naked), and his baritonevoice probably helps.
Although most of the male cast of Karneval could qualify to the point of being full of pretty boys, Gareki is especially seen in cut up or revealing outfits that should not look as hot as they do when he's wearing them.
Aikurō Mikisugi randomly slicks his hair back and removes his glasses to reveal his handsome face while also randomly undoing his clothes and striking erotic poses when he explains how Senketsu works to Ryuko. He does this for no reason other than to annoy Ryuko and make girls watching the show faint. Hell, he even has fangirls who find his old man disguise sexy, despite it clearly not meant to be.
Gamagoori is this for Bara Genre fans. He spends a lot of time shirtless and the show loves drawing attention to his size and muscle mass.
Tsumugu is this for similar reasons to Gamagoori. It helps that he's almost always near-nude.
In Kuroko's Basketball, pretty much all the guys are this. Considering that this is a sports-genre anime, this series has way more attractive male characters than other sports-genre series. From Kagami (with shirtless scene in episode one), Kise who works as a model, to Kuroko himself.
Mobile Suit Gundam Wing: Despite being part of a franchise generally targeted at men (because girls can't possibly be entertained by giant robots and politics), an overwhelming majority of the fanbase was women; women who were unabashedly interested in the male characters of the show for their looks, with maybe personality coming in at a close second. Heero, Duo, Trowa, Quatre, Wufei, Zechs, and Treize all fit this trope. The sheer amount of fanfiction, doushinji and websites dedicated to them (usually of the Ho Yay nature) is testament. IIRC this was done intentionally to broaden their audience demographic. It worked.
On that note; there is PLENTY of Dark And Troubled Pasts (particularly Heero, Duo, Trowa and Zechs), badasses (all of them), pretty boys, questionable moments that fuel the massive amount of yaoi fangirlism, stoicism (Heero and Trowa; although they kind of sorta not really get over their absolute stocism), jerks with hearts of gold, and a Shirtless Scene (maybe — Heero had bandages, but bandages aren't shirts, right?). Depending on your mileage there is Foe Yay (Zechs and Heero always promising to finish their "duel"). So much Woobie (depending on the character it may be Iron or Stoic) it is almost painful to watch at times, considering what the pilots have been through and what they keep going through during the show.
Kou from Monochrome Factor. Troubled past? Check. Emotional and physical scars? Check. Sexy voice? Check. Looks great with his shirt off? Check. Comfortable with man-on-man scenes? Check. Akira and Shirogane are also great examples.
My Hero Academia, being a series about teenagers training to become superheroes has a lot of this. Highlights including:
An anime only Pool Episode featuring every guy in Class 1-A in skintight swim trunks. 13/14 of them have a Heroic Build. The very next episode the whole class chills naked in the hot springs.
Eijiro Kirishima is an even bigger one, as his Hero Costume leaves him completely shirtless, laying out his pecs and six-pack abs for all to see.
Katsuki Bakugo, who goes shirtless in the 3rd Ending and often wears skintight black tank tops. His hero outfit also shows off his impressively sculpted arms.
Shoto Todoroki, the resident Bishōnen, whose fire powers blow up his clothes at the Sports Festival (among other moments) and is acknowledged as the resident Pretty Boy in-universe.
Mirio Togata, whose powers leave him naked - and who spends most of his introductory episode in the nude, showing off his impressive physique, though he is something of a Butterface.
Shindo from Ketsubutsu Academy, who was designed to be Mr. Handsome according to the author and is not only very pretty but has another shirtless costume.
Despite being a gonk, Takeo from My Love Story!! is one of these. In the Beach Episode there's little focus on the girls but a lot on shirtless Takeo. The series subverts the usual image of his character design in that instead of being fat, he's a solid wall of muscle. His girlfriend Yamato finds his muscularity very attractive, several older women have gushed over his muscles, and he even lands a job at a macho gay cafe thanks to his physique. He gets bonus points for being a gentlemanwho's good with kids.
Kaworu Nagisa — the mysterious Fifth Child. Smooth voice, elegant, handsome, and for the few times he's appeared (counting the movies) usually he's either naked, giant and naked, wet, in bed with another guy or in any combination of those.
For the Straw Hats: Luffy, Zoro, Sanji, and Post-Time Skip Usopp. Luffy is handsome and reasonably muscular and his shirt is often unbuttoned; Zoro is ridiculously muscular and frequently appears either shirtless or in an unbuttoned shirt/coat, and Sanji is a Handsome Lech whose occasional shirtless scenes reveal he's as ripped as Zoro is. Post-Time Skip, all three of them have become even hotter, with Sanji gaining a small-but-smart goatee, and Luffy and Zoro both possessing more mature auras and additional scars. After the timeskip, Usopp has become incredibly muscular and much more confident, so he also qualifies.
Luffy, Zoro and Sanji get particular focus in the bath scene from One Piece Film: Z where to fangirls's delight they aren't wearing much. Also, there's an almost naked Aolkiji aka Kuzan in that scene as well as Brook... Dem Bones.
The series also has some very attractive older (as in, middle-age-ish) men, such as Red-Haired Shanks and Captain Smoker. And also Dracule Mihawk, for those who enjoy their men muscular, darker and brooding.
Charlotte Katakuri is certainly this, complete with terminal lack of a shirt and tattoos albiet he has scary teeth. Fans, female and male consider him a Hunk.
As the fandom could attest, the brothers may already be this by default. And when you have officially licensed dakimakura of them and magazine artwork like this◊, it's hard to say that it was unintentional...
Princess Jellyfish: Kuranosuke is a beautiful male who crossdresses as a beautiful female to great effect because he likes to, leading to boatloads of Fanservice, shirtless scenes such as hanging around Tsukimi's apartment in his boxers and running around in just a Modesty Towel, nude scenes, fetish fuel, and inspiring crushes in both males and females. He's drawn as prettier than most of the girls in the setting too and people who look at him think he's a model.
This is kind of the reason why Saint Seiya has a BIG female fanbase.
The most obvious is probably Andromeda Shun, a Reluctant Warrior with a pretty face, in-universe fanclub and big brother complex. The storyline where he's possessed by the god of death doesn't help matters either.
The Sengoku Basara anime contains the gallons of fanservice from the original video game and adds a little more with an injured Date Masamune bandaged shirtless scene. Yowza.
Shimoneta: Oboro is a unique example due to having a woman's face and bodynote In the manga, Oboro's pectoral muscles are flat. The anime differs by shaping them to appear like B-cup breasts, despite being biologically male. Made more apparent during the end credits of episode 9, which briefly shows him fully nude, and episode 12 where he's forced to wear women's lingerie. On fan art sites, some have said they don't care that he's a guy and would (quote): "still hit it anyway."
Blair. Admittedly, it was only during the Book of Eibon arc where all of the characters were gender swapped, but still.
Kid also qualifies.
And then there's Soul and Blackstar who each showed their abs at some points.
Soul mostly considering the scar across his chest, which included a slow pan up of his toned abs at first glance.
Space Dandy has both Ms. Fanservice and Mr. Fanservice— Dandy himself filling the latter role, as one can see in episodes 6 and 8. In 'The War of the Undies and Vests, Baby' Dandy spends 98% of the episode in just his briefs, and in the second half of 'The Lonely Pooch Planet, Baby' we get not one but two pan-ups showing his bare butt, as well as him dressed in just a towel.
Trigun includes quite a lot of fanservice scenes of Vash, including a scene where he strips naked. In the manga, the suit under his coat also includes an ab window. Wolfwood also gets a shirtless scene in the anime, not to mention the amount of "cleavage" he shows off, especially in the movie.
Yuri!!! on Ice focuses on male figure skating, so there's plenty of Female Gaze from the attractive male characters. Victor Nikiforov is a prime example for being a very pretty man whose body gets a lot of attention in the first four episodes while he's in the hotspring and appears in nothing but a speedo when he's near the pool.