I thought about it and I'm not sure if my list is solid or not... I don't believe this is in any particular order either.
5. Sheva
4. Excella
3. Steve
2. Angela
1. Alice
To be fair I don't think I can ever consider either Angela nor Alice to be cannon. Also I'm not really giving Steve Burnside the real chance since I never finished the game. But his character, his voice actor, everything that made him him, I hated. I actually wanted Steve to burn up and suffer for taking the dual handguns. But Nite's analogy for Sheva and Harry Potter was excellent.