Optimus Prime and Bumblebee out of the ones I know.

Blackarachnia, Botanica, Cheetor, Tigatron, Airachnid on the current cartoon, Elite One and her gals Chromia, Moonracer, Firestar and Arcee, Soundwave and Ravage, was my favorite of his cassettes.

Omega Supreme had the greatest saying ever: I am Omega Supreme before cybertron was ..I was...   that or target aquired .. New Target selected Megatron... threat level minimal.... (after a big rant by Megatron on how powerful he was)

scorponok bcuz he is one badassmf..and he's huge!!!....but sucks from the movie

Rodimus Prime

Megatron

Bumblebee FOREVER! I like him even in different universes. but I'll say Iove him more in Transformers: Animated. I mean, he's a super cool and an outgoing young bot who can't stop rambling about how fast he is! (I really like his personality here! ^^)

From the Autobot side of things its bumble bee his courage & selflessness was always great to me but i was never an optimus prime fan still aren't lol but i do like Ultra magnus .

Admit it. He is the coolest G1 autobot EVER!!

i like bumblebee cuz he is yellow