My personal favourite is that red lobster guy (that I don't know the name of) from Viper V12 & F50. When he first popped up, he was just a regular monster rapist thing with a dodgy voice, but when he returned later he took on a more caring, almost paternal role towards the new girl(I must confess that I'm not terribly good with the character names). Watching an alien red lobster(who is previously a rapist) having a heart-to-heart with a young girl is just one scene that had an irresistible, surreal appeal for me. I enjoyed his later, heroic effort to(if I got the gist of it correctly) face-off against Bravan before the girl could, so as to keep her out of harm's way, and his death right before she turns up is probably the most heart-breaking scene I've witnessed in the Viper series.
"Lobster-guy" is a named Kuwagata-donar. And he's a stag beetle (kuwagatamushi) not a lobster. His young friend is Mari.
...not because I like him that much, more like a lack of options...
We have plenty. Here's what we have to choose from (considering only the primary characters):
Afternoon: the pageant host and three directors
Alien War: the three aliens (General Shin, Aru, and Dor)
Angel Dust: Walder and his two henchmen
Animahjong: the protagonist, the sister's father, X, and Tommy (altough the last is only 2 so I'm not sure he should count)
Children's Play: Senpai
Demon's Night: Ryuu, Dyna, and the demon
Double Impact: the lord of the house and two guardsmen
F40: Lloyd, Fauzen, Mark, Sheila's doctor, Gordy, Keen, and Ryuu
Friday the 13th: Eric, Fritz, and, if you count him seperately, J-SON
Future Investigator Bravan: Bravan, Kuwagata-donar (stag beetle), Koumori-donar (bat), Dokubachi-donar (wasp), Kamakiri-donar (mantis), Mimizu-donar (earthworm), Iwagame-donar (turtle), and Skeleton Boss. I leave out Iwa-donar (squid) becuase one of the V series stories reveals that donarghe to be female. Also leaving out Colonel Gell when she takes the form of Shine's dead boyfriend.
Green Boy: Taneo and the mysterious man from the Green Leaves
Guynarock: the alien boss and at least two subordinates (all believed to be male)
Imagine: Toshiyuki
Island: Dice Punk
Komachikawa Detective Agency: Voss, the kid
M3: Kenji, Koushi
M5: Tsubasa, Kazuhiko, Rokurou, and Kuroda
Magical Gambler Totocal Chomi: Sai and the three Mahjong Club members (Jai, Kyou, and Sunekichi)
My Mothers: Grandpa, Oneesan
Northern Lights: Captain, Takeshi, Osamu, and the young triplets at the dojo
Paradice: Cardboard Man
Rear Under: Boss and his two commandos
Reserve: Shou and Lucifer
Rise: Seed, Seed's blue subordinate, Seed's green subordinate, Kiese, Tarma, Hrmoni, and Aoki
RSR: Elan, Alfa, Diablo, Veloce, and Maranelo
The Devil Came...:: Ogawa, Jouichirou, and Alpina
The May Works: Cavat (I don't think Slime should count, as he/she/it merely changes his/her/its shape to be male at the time)
Vision: You
I'll give my vote to Bravan but nods to X, the aforementioned Kuwagata-donar, Tsubasa, Kazuhiko, Mika's grandpa, Captain, Elan, Seed, Ogawa, Jouichirou and Alpina.
