As a rule of thumb, in almost EVERY Japanese or East Asian fighting game, when your character is K.O'ed and the words "K.O" appears, it's ALWAYS spelled or announced as K.O. instead of Knock-out, since it's impossible to pronounce that word in many East Asian languages.
SNK may well be the kings of this trope, as any foreign character in their games will have Engrish in their quotes.
Iori Yagami of King of Fighters has an image song, "Kaze no Allegory", where he sings "Don't break my soul, woah oah tonight".
Krauser, unlike other SNK characters, has been voiced by English-speaking actors in almost every game he's been (Michael Beard in Fatal Fury 2 and Fatal Fury Special, and B.J. Love in KOF and Real Bout games).
On the subject of the Rockman.EXE series: in the original Japanese, Eleki Hakushaku (Count Zap) often spoke in gratuitous English. There, we got such gems as "Yeah! Rock and Roll!" and "God Damn." Of course, the dubs have no way of translating.
In the X series, all the games after X5 use Gratuitous English in the names of the bosses. This ended up with atrocities like Metal Shark Player, Infinity Mijinion, and Tornado Tonion.
The boss names in the Japanese versions of X1-5 use Gratuitous English as well — it's just they started translating the names more literally from X6 onwards.
The names of X's weapons are also this trope. This became... interesting once he started calling his attacks in later games.
All the characters from Castle Shikigami 2 speak in horribly butchered English and make so little sense that it falls into the So Bad, It's Good category. Especially notable because the voice actors were native English speakers who had to read the Engrish(Though sometimes they would correct it).
Chipp Zanuff from Guilty Gear is supposed to be an American who doesn't know Japanese, but due to the Translation Convention of the game he speaks it most of the time anyway. This is balanced by his large amount of gratuitous English, usually when swearing or surprised ("HOLY ZEN!"). The example here also points out his inversion in gratuitous Japanese. Like in that example, on the rare occaisions he's actually using Japanese, rather than it being an effect of the Translation Convention, it's random nonsense that makes no sense in context—he actually shouts "sushi" during one of his attacks, for another example.
In addition, about 75% of the attacks in the games are called out in English. This ranges from the good (Chipp and Sol Badguy call their attacks with Surprisingly Good English for the most part) to the laughable (Venom's Double Head Morbid: "DOUBAH HEAD MORBIDOH!").
The PS2 version of Guilty Gear X had pretty terrible English, every single fight. "Are you ready? Let's go! Let's enjoy a great time!" And... "Heaben o' Hell. Doo wan. Lez rock." This was replaced by better a better English speaker in the English version of Guilty Gear XX...at least until Accent Core, where they replaced the old speaker with a worse one for some infathomable reason when the original/#Reload/Slash speaker was perfect.
You also get a lot of this in Guilty Gear's spiritual successor BlazBlue. Try performing Ragna's "Gauntlet Hades" and watch how the Japanese voice actor mangles the phrase. And don't get me started on "The Wheel Of Fate Is Turning". Of course, you can set the game to English voice actors as well.
GAUNTORETTO HAHDEHZ! GORILLA FATE IS TOINING!
IZOCHI SUPAA KURASH!
The same developer gives us this in their Fist of the North Star fighting game: "The Time of Retribution. Battle (1,2,etc). Decide the Destiny!" Probably one of their better attempts.
In a similar vein, Sodom from the Final Fight and Street Fighter games is an American who's trying to be Japanese. He actually inverts the trope because he never speaks English, but instead speaks Gratuitous Japanese by mashing English words together that sound like Japanese phrases. For example, when trying to say "shoushi senban" (meaning "truly pathetic") he says "SHOW SEA SEND BANG!"
One Japanese Kirby Super StarStrategy Guide featured a Great Cave Offensive comic (it read left-to-right a la a Western comic book) at one point, that featured a fedora-wearing Kirby with oddly masculine features in a nonsensical Indiana Jones spoof. The kicker? The people writing the guide apparently wrote it in Japanese first, then translated it into English themselves — as a result, we got gems like "More SKINNY, less ATTRACTIVE to my baby!", "Gra'ma said, NO PICK up EVIL", and, best of all, "SHIT!".
This often extends to names, too: in Final Fantasy VI, the name Tina was considered exotic. If you don't recognise them, they were somewhat thankfully re-translated into English when they were translated, so the character became Terra. And then there's the whole "Claude and Alice" rumour.
Then there's Siegfried, who abandons battle with some gratuitous Spanish. "Adios Amigos!"
The entire Final Fantasy franchise in general LOVES it self some Gratuitous Foreign Language. The names of almost everything- titles included- are pronounced the same way in Japanese as English. Example: "Barret Wallace" is pronounced roughly "Bayrlet Walrus."
In an interesting gaming parallel, the SSX series of made-in-Canada snowboarding games features a Japanese character, Kaori, who speaks in a 50/50 mish-mash of fluent Japanese and extremely accented gratuitous English. Given the lack of other non-English-fluent characters, the makers were apparently trying to jointly appeal to trendy Japanese audiences and American fans of Japanese culture. Interestingly, this lack of fluency doesn't impede her interaction with the other snowboarders at all, even a romantic interest.
The X-Men arcade game has many plainly spoken engrish phrases, including "Pyro will burn you to toast!", "I am Magneto, Master of Magnet!", "Magneto is in another place" and the (in)famous "X-Men, welcome to die!" as spoken by Magneto. (This line was parodied in Marvel vs. Capcom 3.) While not exactly engrish, he also makes the ridiculous insult of "X-chicken!"
More X-Men engrish: the first Japanese theme song produced when the '90s animated series was brought to Japan has a few random English phrases. The most obvious one is at the end where the singer practically screams with much gusto the line "CRY FOR THE MOON!"
The Japanese version of Street Fighter III: 3rd Strike has the memorable "Let's Blocking" intro for the parry practice bonus stage. (Blocking is what parrying is called in Japanese, but the incongruous "let's" is what makes it Made of Win.
The Japanese track of Street Fighter IV has a lot of this when calling attacks and giving introductions. Particularly amusing are Balrog (the boxer), who shouts nothing but Engrish in the Japanese track, and El Fuerte, who is Mexican.
Cammy from the same game also supplies with some Gratuitous English, such as (among other things) saying "Mission complete" when she wins a fight, and calling her attacks (as expected from a Fighting Game), all of which are in English.
Also of note is Rolento's victory phrase in Street Fighter Alpha 2/3: MISSHON KONPURIITO.
In the Japanese version of Tales of Vesperia, villain Yeager speaks in a rather peculiar manner, randomly interjecting English words and phrases where Japanese would have sufficed, such as "Come on, boy!", and "Oh my god...". Naturally, his manner of speaking was completely changed in the English dub ...into Gratuitous German!
Karol has a somewhat unusual case in that the names of his arts in the Japanese dub are half Japanese and half English in their pronunciation (Examples being Houshuu Thunder and Kasshin Heal Stamp), perhaps to reflect his childish nature.
There once was a young elf named Genius Whose English name was God's gift to limerick writers...
Any Tales Of game will feature this, for this reason: While most weapon techniques are three-to-five kanji compounds, spells are generally named in English. Now remember that the series has had voice acting since the beginning, and, well... faastueido!fiafurufurea!shirufu! And for the exceptions who have their tech names in Gratuitous English, this applies again. There are also a few examples of Gratuitous French and Gratuitous German techs, as well.
The intro to the North American release of the third game has the same intro song from the original sung completely in English. It's something to behold.
The Persona games have a weird relationship with this trope:
Persona 2 features the famous "LET'S POSITIVE THINKING!"
Persona 3 and 4 however, feature much gratuitious English in almost all their vocal songs, most notably the intro screens and battle music... except it's surprisingly good. There are plenty of parts where words are misemphasized or mispronounced, but if you know what they're trying to say, it actually makes sense.
The slogan for Junes in Persona 4 is the nonsensical "Everyday younglife Junes", which was changed in the English translation to something that makes a little more sense.
Which isn't all that bad, but there are characters named Load Ran and Really Till.
A number of the songs from Katamari Damacy are loaded with Gratuitous English, including the Title Theme Tune "Katamari On the Rocks" ("Don't Worry, Do Your Best / Picnic kibun Feels So Good / Suteki na Afternoon / Furachi no Midnight, Yeah!") and "Song for the King of Kings" from We Love Katamari ("Everyday, Everynight / Kimi to ousama no Rainbow, Yes!")
Although, since this is Katamari we're talking about, it sorta makes sense.
The voice clips in the American versions of Cooking Mama are entirely this, ranging from simple stilted-sounding R/L inversion ("Look, a swarrowtail butterfry!" in Gardening Mama) to more awkward sounding phrases ("DON-TUH WARRY, MAMA WILL FEEX EET" and "WUNDAFAH! EVEN BEDDAZEN MAMA!" in Dinner With Friends)
Cooking Mama 2 has "Great! Yuu gayvid yua best effah!" ("Great! You gave it your best effort!") "Don warri, Mama will fix zis" and "Triffic! Even bettah zan Mama!"
DO NOT MIND
Averted by Knights in the Nightmare. The Japanese version is fully voice acted in English, and while the delivery is often highly enunciated for the Japanese audience, leading to alternate cheese and ham, it's still good English with a good accent. Atlus even saw fit to leave it in during localization, probably for the occasional Narm Charm.
Sadly, this only holds true for the voice acting. The Japanese version of the game also featured a lot of English text, including such instant classics as "How to Reinforce Least Knight" and "Touch the Box to Be Defeated Enemy".
"Welcome to MOTHER3 World." Also, the voice clip played when you name your characters is Itoi himself saying, "OK desu ka?" (Is this OK?) According to Itoi, he was tricked into saying it by Hirokazu Tanaka (who had a tape recorder behind his back).
The attack names in Eternal Sonata are mostly in gratuitous English (Even on the English language track, which just has the English voice actors say the original phrase), with Chopin getting lines in gratuitous French and Italian. Fortunately they make a reasonable amount of sense.
In the PS game "Speed Power Gunbike," the game over screen happily informs you that "Anergy empty! You all over!"
In the Japanese versions of Snatcher, JUNKER was originally an acronym for "Judgement Uninfected Naked-Kind Execute Ranger".
The MSX version of Metal Gear gave us such well named villains such as the "Shoot Gunner" and "Coward Duck". The sequel, Metal Gear 2: Solid Snake, isn't much better with the likes of "Black Color", "Ultrabox" (named after the New Wave Music band Ultravox) and "Night Sight".
But the point is that "Black Color" was how the name was spelled in the actual game itself. Many people assume its a misromanization by the fan-translators, but that's how it was spelled in the actual Japanese game (all the bosses had their names spelled in roman script).
Blazing Star, and it's memetic "YOU FAIL IT! YOUR SKILL IS NOT ENOUGH" screen. Then there's the female announcer who yells English phrases such as "BONUS!" with hilarious results.
The very name Donkey Kong is perhaps the most famous example of this trope.
In the French version of Team Fortress 2, one can hear the Spy scream, "Oh my God", in English as part of his Jarate responses. What makes this strange is that he says that phrase in French in the original English version (and all of the other languages the game was dubbed in), suggesting an attempt to Keep It Foreign.
From DoDonPachi DaiFukkatsu Black Label's Arrange mode: "Just a couple more shots desu!"
Misha's "Bush Cheney 2004" shirt from Katawa Shoujo is probably meant to parody this trope.
This is fairly common in the song lyrics in Deardrops and Kira-Kira. It's pointed out that some of the band members have no idea what they actually mean.
The names of Aether Relics in Duel Savior Destiny are frequently in gratuitous English and have little real meaning. For example, the sword Traitor is perfectly faithful to Taiga. Though Traitor is actually the subversion of this trend of the name meaning nothing: Traitor is rebelling against God.
In Way of the Samurai 4, members of the British faction sometimes speak in heavily-accented Engrish. Of particular note are the photographers, who act as your Save Points in the game, and speak to you in broken English ("Hold still unmoving, please!"), somewhat justified by the language barrier between your samurai and the British nationals (until the language school opens up, most of the other foreigners won't be able to understand you at all).
Aside from the title itself, Time Gal gives us "STOPPU!" Time Gal yells this whenever a Time Stop is performed. The very last time this is done in the game, she yells out the whole phrase, minus the extra syllable.
Played With in Little Busters: Kud is a foreigner who is constantly speaking in broken English... because it isn't her first language and she's really, really terrible at it, so she uses every opportunity she can get to practice it. For a straighter example, Komari speaks in English for a couple of her battle phrases, though her pronunciation is much better.
Some Nintendo-developed game with voiced cutscenes will have only English voice acting, even in the original Japanese release. A great example can be found in the intro cinematic of Pikmin 3, which is entirely in English, with added Japanese subtitles.
One of the clues in the first murder case in Danganronpa made the identity of the killer extremely obvious to English-speakers from the get-go. The victim wrote "LEON" (for Leon Kuwata) in english upside-down behind her before dying. Because all the characters involved are Japanese high-school students, though, most of them thought it was the number 11037.
The Japanese version of Team Fortress 2 keeps the English names for the player classes, thus, turning their names into this trope. In addition, only the interface's translated - the voice acting stays in English (at least by default).
The intro screens for Great Mahou Daisakusen have English captions in massive screaming letters, subtitled in much smaller Japanese.