Although Gin, the protagonist of Ginga Nagareboshi Gin, is named for the Japanese word for "silver", western fans probably can't be blamed if the first thing they think of when they read the name is a certain alcoholic beverage. The Japanese spelling makes the correct pronunciation very clear, though. Admittedly one of the tamer cases... especially when one considers that his son is named Weed.
More hilarious than unfortunate, but one of the wolves in Nagareboshi Gin is named Red Bull. He gives no one wings, though.
Speed Racer, probably. Honestly, who names their kid "Speed"?
Speed: What kind of a name is "Spritle"? That's not even a word! Spritle: You think my name is bad? Your name is the rate of motion expressed via distance traveled per units of time!
The kind of people who're prophetic enough to know that their son will be the greatest racer ever. (And they themselves are named "Mom" and "Pops", so...)
Pops: What do you guys have to complain about? My wife's name is "Mom". "MOM"! Do you have any idea how awkward that is? Do you have any idea how awkward that is during sex? (All quotes from the Awesome Series)
Artifacts of translation, of course, as noted in the Speed Racer article itself. Mifune Go is more properly a Punny Name.
Subverted in one of the older comics' first volumes where Speed's name is actually Greg. The Media kept calling him "Speed" instead, so he just went along with it after a while. Probably done to justify the "G" on his shirt, though, which comes from "Go", his original name.
The eponymous teacher from Sayonara, Zetsubou-Sensei — Nozomu Itoshiki — counts. Thanks to the kanji used in his family name, his full name, read as a single word, can mean "despair". Likewise, the name of his immediate older brother Mikoto can be read as "death" (ironic enough for a doctor), his younger sister Rin "unequaled [in sexual prowess]", his other (estranged) brother Enishi "disinherited", and Enishi's son Majiru "breakup" (on account of having to freeload with his youngest uncle, Nozomu). It also extends to the rest of the characters, several of whom consider marriage just to get out of it.
But then, the entire series is based around these puns, so it's not surprising.
Kamina from Tengen Toppa Gurren Lagann may not have that weird a name, but woe betide you if you mispronounce the "m" as "n" — yes, that happens, there is a reason why people say "M for Malta and N for Norway". "Kanina" is Hokkien for "fuck your mother".
If Kamina's name is pronounced as "Kuh-mean-uh" rather than the Japanese "Kah-mee-nah", it becomes the word for "bastard" in Hindi and Urdu. (A native speaker wouldn't make this error due to the vowel length distinction in Indian languages)
In Spanish, Kamina sounds the same as the Spanish word Camina ("To walk", translated more or less literally)
It might not mean much, but a space between Kami- and -na means "our turn" in Filipino.
Kamina itself sounds too much of a feminine name, if you take in consideration the termination -na is mostly used for girl names.
It's likely an accident, but both the original and dub pronunciations of Simon's name sounds a bit too much like "Simone", (which is a girl's name) and "semen", which given the show's themes of genetic material and suspiciously large drills, may be more than slightly appropriate.
Another example is "Rinkane Jail", which sounds a lot like "rinkan", which means gang-rape.
Yet another example: Viral's first mech is called Enki, which is fine. His second is called Enkidu, which is also a neat reference to The Epic of Gilgamesh. His third is called Enkidudu, which probably sounds OK to a Japanese person, but to an English-speaker...
In the dub of Ultimate Muscle, Gazelleman is called Dik Dik van Dik, after a very small type of deer. This is more than likely deliberate; when Adam Sessler reviewed one of the games based off the series and it became a Catch Phrase of sorts for the next year or so.
Not to mention, in Dutch his name means fat fat of fat.
"Dikdik" also means "pulverize" in Filipino, making instead an Awesome McCoolname in that country.
In the Baccano! anime adaptation and light novels, one of the storylines revolves around the hijacking of a train by a cult, a working-class street gang, and The Mafia. This train just happens to be called The Flying Pussyfoot.
Just as bad has to be the name of one of the more prominent characters on board that train: Jacuzzi Splot. The DVD Commentary even makes note of this.
"Bajeena" has actually been romanised as "Vagina" on at least some official merchandise.
And Kiki from 08th MS Team would be un-PC in the Philippines. Kiki in Filipino means pussy.
Similarly, the Miyazaki film Kiki's Delivery Service ran into this same problem, so they changed the protagonist's name.
Speaking of the above, Filipinos made an admirable effort in not minding the title Pokémon, which, without the last letter, sounds like the Filipino term, often used as a curse, "your pussy."
At least two different regional language dialect in Indonesia (they swap e's and o's with i's and u's respectively) will render Pokemon into Pukimun. The problem? The italic part is also a rather crass slang for female genitalia.
Mobile Suit Gundam ZZ had Elpeo Puru, a young pilot named after Lemon/L People (Eru Pīpuru), a popular hentai magazine with an unhealthy focus on young girls. Given the unsettling hints about her handler Glemmy's proclivities, this is appropriate in all the wrong ways.
Of course, Laputa was adapted from Johnathan Swift, who likely named the island that on purpose.
All of the Innovators of Gundam 00 have odd names, which besides those of Tieria and Ribbons tend to be verbs changed into nouns (as in Healing/Hilling Care). One's name is Bring Stability, but the name has also been translated as BringStabbity.
Gundam Age brings us Natora Einus (yes, it is pronounced that way).
Kankuro's name from Naruto in both Hungarian dubs is usually pronounced so that it sounds dangerously close to (or exactly like) the language's equivalent of the seldom used expression "boar-fucker". Thankfully, it's not something you can hear every day, so the name didn't have to be changed.
Bleach: Ichigo's family name "Kurosaki" sounds suspiciously like the Hungarian for "expert fucker".
Space Battleship Yamato's main protagonist was spared of major snickering in the Philippines since it was the American-dubbed Starblazers that was shown, along with its American names... until the original subbed reached its shores. Susumu is a... very fond way of saying "susu mo", which is the Filipino for "your nipple."
In Indonesian however, 'Susumu' carries a lot more unfortunate implications as it refers to the whole organ in question (if in a rather childish way).
Haja, in Rave Master. His name means evil. It's like his parents knew his future.
They are the elite Destron soldiers in Transformers Victory; Transformers cower in fear in just hearing their name. They are... the Breastforce!
Sai Argyle from Gundam SEED: "Sai" is Hokkien for "shit".
His last name is unfortunate, too. Who would want to be named for a pattern most people associate with socks?
The lead character of Soukou no Strain usually refers to her mech by its number in the formation, that being "Strain EX". Its actual name? Ram-Dass. Like "Laputa", it's a literary allusion that the production team doesn't seem to have realized sounds dirty.
The Death Note spinoff Another Note has someone named Backyard Bottomslash.
For that matter, L's mentor's real name is Quillsh Wammy, a name likely to lead to snickers among English speakers.
Despite the character shouldn't be taken too seriously anyway, it can be difficult to take Maria Osawa from Canaan seriously because her name is one dakutennote two dots written above a Japanese character off from the (in)famous Japanese porn star Maria Ozawa.
Chikubi, the class hamster in Mitsudomoe. The little guy's name means "Nipples", chosen because boob-lover Futaba thought his tail reminded her of one. The name stuck.
The name of one of the Spectres in Saint Seiya is... Troll Ivan. Take that as you will.
Dragon Ball gives us Bulma and Chi-Chi, whose names mean "bloomers" and "breasts" respectively. In fact, Bulma's family is this trope thanks to Theme Naming (her family's names being under garment themed). And Bulma's daughter is named Bra, which often gets translated to "Bula" to try and lessen this.
In the Portuguese dub, Chi-Chi's name was changed to Quica (pronounced Kika, short for Francisca) because her original name means "pee". Likewise, Goku is always called by his full name (Son Goku, abreviated to Song in the original anime) probably because Goku could be interpreted (and sometimes still is) as a mix of "cocó" (poo) and cu (ass).
There's also nature loving genie Mr Popo. In German, "popo" is slang for "butt".
There were also the Vegetans, whose planet was originally called "Plant". That makes them the Plantians, which sounds like an anagram for a special type of banana.
While Hao from Shaman King has a perfectly respectable name in Japan, he spends a good portion of his life as a Native American.
All of these are intentional; several names are references to a musician, band, or song.
Claymore contains a minor character named Uranus. She has a rather dirty fighting style. Fortunately for less mature English-speaking readers, she is killed off a few pages after being introduced.
Silk Koharuno's given name in Ultimate Girls. Did her parents really mean to name her after the stuff girls' underwear is made of? (Obviously, the writers sure did, considering what kind of a show this is.)
The writer for Bokura no Hentai, which roughly translates to "Our Abnormalities", mentions that the name of the series is this. When people hear the "hentai" in the title they think it's, well, a hentai.
Under similar accounts, xxxHOLiC is often looked at askew due to its name. In Japan, the "xxx" in the name means the unknown, but most westerners link "xxx" to either pornography or moonshine.
Blame the dub for this one (it was only the case there) but in Yu-Gi-Oh! GX, there was X from the second season, one of Judai's opponents who played a Mill Deck. His full name, in the dub only, was Howard X. Miller. (More than a few fans groaned when they heard that one.)
In Medabots, Ikki is this to English speakers. Because most people will instinctively read it as "Icky", and it was reinforced by the English dub which pronounced it as such. It's actually pronounced E-key.
It's no wonder Charles zi Britannia's has a pretty contentious relationship with his kids with his naming choices. You have Lelouch, Nunnally, Odysseus, Schneizel, Cornelia, Clovis, and Euphemia. Given they are all supposed to be from a tremendously long line of British emperors, their names are probably chosen to reflect that overly-dignified stuffiness.