1/Powered Up: Bombman/Oilman (Not much to explain about Bombman, but Oilman just acts... odd to me.)
2: Woodman (Is he a robot with a wood exterior? What's the deal with this?! It's getting old!)
3:
Breakman Magnet Man (MM8BDM-Classes and MM3-wise. Not great)
4: Toad Man (Being picky here, but why did he exist?)
5: Gyro Man (Neat concept, not great in practice)
6: Blizzard Man (Weapon sucked, and so was his stage. The battle is mediocre at best)
7: I don't hate all of them, though the least favorite of the bunch is Cloudman.
8: Aqua Man (YOU CAN CALL ME-- Please get a gun)
B: I agree with Lamp, Tenguman and Astroman stole spots for the robot masters, at least Tenguman's weapon is better...
9: MIKE! I LOVE EVERY ROBOT MASTER!! So I will say my favorite is Splashwoman (Because we never got a Female RM until now), and Tornadoman. (Never played the game though, only the demo)
10: Least favorite is Strikeman, I like all the robot masters though. Strikeman has the sports theme which places him on the non-hate list.
Main: Difficult, but i'm going with Protoman.
Killers/8BDMKillers: Quint/Punk (Punk for being Poseidon's Salty Butthole and always screwing me over by one shotting me with the Screw Slam.)
Bonus in spoilers!
X Series, gonna run it through:
X1: Spark Mandrill (Just what-)
X2: Wire Sponge (What is your japanese name? Because YOU DON'T LOOK LIKE SPONGE, YOU'RE PUKE COLORED!!)
X-Hunters: Viola (Don't get the idea behind him, and he's hard as hell)
X3: Blast Hornet (...What else is there to say?)
X4: Web Spider (Nuff said)
X5: Duff Mcwhalen (Long stage is long)
X6: Blaze Heatnix (Boss fight would be fun, but the Nightmare Snakes/Donuts ruin the experience before you get to him, f^#% that guy)
X7 and X8 I have not played... But Tornado Tonion from X7 has a voice too high in tone to really take seriously, WHY?!
And yeah, that's about it.