I don't think either faction gets better toys. Both side have had really great figures, and really shitty ones.
Bruticus, Devastator, Lugnut, Blitzwing, Predaking, Tidal Wave, Overlord, Starscream. I can do this all day.
Decepticons! because theres all way needs to be another biger bader robot so the autobots can fine away to beat it.
Decepticons have more interesting designs usually leading to more fun toys for me. The Autobots are just all cars so they're kind of boring.
I'd say Decepticons get better toys overall made. Or at least more unique and intruiging designs that can catch my intrest more often.
Hmm, toughie. I love all the Classics, but the Autobots from that line really POP when you line them up. On the other hand, for the movie line the Decepticons clearly dominate.
In Beast Wars, I almost exclusively got Predacons. They got excellent figures. In Animated it was mostly a tie, but I was again biased and went towards the 'cons. Great molds all around. It's just that the bad guys tend to have more variety and appealing desings (for me) in all TF toylines.