Well I actually based my waifu selection on an RPG party like system just to help me choose.
Kasumi (Dead or Alive) -Ninja-
Kasumi, also known as "the Kunoichi of Destiny", is a female ninja skilled in the Mugen Tenshin Style of Ninjutsu. She was to become the 18th Master of the Mugen Tenshin Ninja Clan, but ran away in order to enter the Dead or Alive tournament. There, she hoped to defeat Raidou, the man responsible for crippling her brother Hayate.
She is basically one of two characters in the game that I can play well with. The other being Ryu, while GAR not waifu material. Background material on her is pretty scarce due to the nature of fighting games but she is shown to be a compassionate and kind though willing to kill when need be.
Of course, she is also very hot
Kasumi fills my thief/ninja niche
Mikuru Nazume (Zero In) -Gunner-
Private police officer and gunman extraordinaire, Mikuru also has a policy of not killing anyone. Accurate at range and more than capable at CQC, she is more then able to capture criminals.
Little bit of tsundare, horrible cook, naive to a fault, and a looker all rolled into one.
Fills the ranger/distance fighter niche
Mint Adnade (Tales of Phantasia) -Healer-
After having her village burnt down, she was thrown in a dungeon to rot with her mother. Being saved by Cless shortly after, she joins Cless in his adventure to escape. After finding out about Dhaos and his potential of destroying the world, she is sent back in time with Cless by Morrison so that Dhaos could be stopped. She finds that there is still hope in saving the lands from Dhaos. She seems to remain gentle and calm throughout most of the adventure. Many of her spells in battle revolve around healing and support magic.
The character I liked the most from the first RPG that I ever played. Cute, strong healer that saved my ass more than I would like and just a classic.
Fills healer and some minor magician niche
Riesz (Seiken Densetsu 3) -Lancer-
Riesz is the princess of the mountainous Wind Kingdom of Laurent, and captain of its Amazon army. After her mother, Minerva, dies while giving birth to her younger brother, Elliott, Riesz vows to take care of him. However, two mysterious ninjas from Nevarl, Bill and Ben, discreetly trick Elliott into turning off Laurent's protective winds and kidnap him. With the winds gone, Nevarl attacks Laurent with a cloud of sleep powder and kills its king, Joster. Devastated, Riesz makes her escape.
Second RPG I've played and by far my favorite for the SNES era. Beyond her looks and large amounts of eroge based on her, she is my favorite character in the game. Strong, buffs and debuffs, and summons.
Fills the front line fighter niche