Pretty much ANY RotF Scout Class, EXCEPT Scalpel, but especially Ejector. Toaster alt mode aside (which is hilarious), his robot mode looks like the Devil. Horns? Check. Digitigrade legs with what looks like cloven hooves? Check. Fangs? Check. Evil looking eyes? Check. Tail? Check. And he has two sets of forearms, too!
Ransack is a must-have, if only because there's no other biplane in the history of Transformers - and it'd be fun to take six or more of them and repaint all the Seekers as their Hearts of Steel versions.
The two motorcycles are basically male versions of Arcee, so they're decent, though not awesome.
Rollbar is wonderful if only for his repaint potential - UPS, Fed Ex, Snap-On Tools, whatever.

The cars are okay, but they "feel" more like Speed Planet designs from Galaxy Force / Cybertron than movie figures.