Vagrant Story (PS1)

Cross-Series (Final Fantasy Tactics): There's an item called "Agrias's Balm" with the description "Balm used by the great knight Agrias as told in the Zodiac Brave Story". Agrias is a character in Final Fantasy Tactics and "Zodiac Brave Story" is another name for FFT. (Credit: Crawl and 1000)
Status: TRUE: Verified by FO.

Cross-Series (Final Fantasy Tactics): In the beginning there's a quote from A.J. Durai, which is a reference to Alazam Durai from Final Fantasy Tactics. (Credit: Crawl and 1000)
Status: TRUE: Verified by FO.

Literature (Hamlet): Rosencrantz and Guildenstern are named after characters in Hamlet. (Credit: Crawl and 1000)
Status: TRUE: Verified by FO.

Van Helsing (PS2/XBOX)

Cross-Series (Castlevania): In one of the early levels there are bookcases. If you examine one, the game makes a reference to the Belmonts of the Castlevania series. (Credit: Kurt Kalata)
Status: TRUE: Verified by FO. Source, Castlevania Dungeon.

Viewtiful Joe (GCN/PS2)

Cross-Series (R.O.B.): There is a picture of a R.O.B. on the back of Viewtiful Joe's case. (Credit: Codie Martin)
Status: TRUE: Verified by FO.

Cross-Series (Super Mario Bros.): If you hold down the X button, Joe will throw up a bomb, jiggle it on his knee, and whistle the first 6 notes of the Mario theme. If you do it in mid-air, he'll whistle another part of the Mario theme. If you do it in Slow Motion, he'll whistle another part. Pretty cool, huh? (Credit: Deven711)
Status: Unverified

Console (Gamecube): Sometimes the third boss, Gran Bruce, spits out a Nintendo Gamecube. (Credit: Deven711)
Status: Unverified

Cross-Series (R.O.B.): The robots in the background of the Final Level look VERY similar to the R.O.B. (Credit: Deven711)
Status: Unverified

Cross-Series (Mega Man): In the Hulk Davidson boss intro, when Hulk asks Joe about the V-Watch, he says "Who do you think you are? Some kind of Mega Man or something?", a reference to the Mega Man series. (Credit: Deven711)
Status: Unverified

Movie (Star Wars): In the second-to-last boss intro, Captain Blue (The Boss) says "Sylvia, I am your father.". It sorta resembles Star Wars where Darth Vader tells Luke "Luke, I am your father." But Luke screams "NOOOOOOOOOOOOOOOOO!" and Sylvia tells him that her mom told her that her dad died. Kinda strange, huh? (Credit: Deven711)
Status: Unverified

Cross-Series (Devil May Cry): Dante from Devil May Cry is a recruitable character in the PS2 version. (Credit: MJB817)
Status: Unverified

Cross-Series (Gargoyle's Quest): The first room of level 2-2 has Firebrand statues in the background. (Credit: Magical Yard Gnome)
Status: Unverified

Famous Person (Various): The boss Hulk Davidson is probably a reference to Hulk Hogan and Harley Davidson. (Credit: Magical Yard Gnome)
Status: Unverified

Famous Person (Guns n Roses): The Joker miniboss appears to be an homage to Slash of Guns n' Roses. He uses guns, wears a rose, and also wears a huge top hat like Slash's. (Credit: Magical Yard Gnome)
Status: Unverified

Movie (Some Like it Hot): The stage "Some Like It Red Hot" has its name derived from the Marilyn Monroe movie "Some Like It Hot". (Credit: Codie Martin)
Status: Unverified

Movie (20,000 Leagues Under the Sea): The stage "20,000,000 Leagues Under The Sea" has its name derived from the movie "20,000 Leagues Under The Sea". (Credit: Codie Martin)
Status: Unverified

Virtua Cop 2 (DC)

Cross-Series (Shenmue): There are a lot of Sega related signs in the background. In the subway there is even a Shenmue poster. (Credit: Hussein)
Status: TRUE: (Screenshot) from MobyGames.com proves it.

Virtual On: Oratorio Tangram (DC)

Anime (Various): This game is a 3D robot fighting game. Most robots, however, were inspired by other robots. Cypher is inspired by Transformers (He's the only one who can transform, and his architecture is reminiscent of Transformers). Specineff is based on the main robot from the anime Neon Genesis Evangelion. Angelan is very Final Fantasy inspired, seeing as though she uses a staff I recall seeing in an FF game, and uses magic. This is odd, since all the other robots use lasers and missles and whatnot. Grys-Vk resembles some of the shorter anime robots, such as Gasaraki's robots and Votoms. Temjin, and the Apharmds are Gundam inspired. There may be other references, since they're a very diverse ensemble of mechs, but I'm not sure what. Also, Katoki Hajime, famed mech designer, designed these robots. You can see some references and nuances to his other robots in his work. (Credit: Bill)
Status: Unverified

Anime (Gundam): The sound effect Temjin makes while throwing a bomb is that of the Gundam-rising sound effect from various Gundam series. The sound effect is very distinguishable, so I can be sure of this. (Credit: Bill)
Status: Unverified