The thread title says it all. To start offf with, the best Starscream is, of course, the white Masterpeice version. For Bumblebee, it would have to be from Henkei.
I think the animated versions of any figure are the best with the exception on G! jetfire which is the best all time fig
Soundwave: Titanium (I keed of course, damn diaper) Jetfire: I'd have to say Classics. That mold is great and avoids the copyright thingie.
My personal favorites: Cyberton Leader Optimus Prime Beast Wars Megatron Beast Machines Cheetor TFA Blackarachnia Beast Wars Waspinator TFTM Ironhide (I like the badass truck mode more than the red microvan!) ROTF Wheelie I'm sure that there are a ton more, but this makes me happy for now...
Masterpiece Megatron, then Animated Leader Megs Animated Shockwave G1 Soundwave Masterpiece Convoy Universe Inferno Universe Prowl, then Animated Animated Blurr Masterpiece Starscream, then Revenge of the Fallen Starscream (I really, really like his transformation)
Prime- Masterpiece, close second Classics Megs- Masterpiece, close second Animated Grim - Masterpiece close second Alt Jetfire - Classics close second G1 Cyclonus - Universe 2.0 Menasor - G1 Bruticus - G1 Ultra Magnus- Classics + FP add on set Mirage - Alt Rodimus - Alt Prowl - Alt Sunstreaker -Universe 2.0 Sideswipe - Universe 2.0 Hound - Universe 2.0 Wreckgar - Animated Blurr - Animated Black A- Animated Screamer - Masterpiece, close second Classics