I would be happy if Hasbro took a step back and revised their entire approach. My favorite vehicles in the Star Wars line have been the ones that are proportional to themselves and the figures -- the newer X-Wing, the newer Slave I... even the ginormous Millennium Falcon they did some years back -- it wasn't properly to scale with the figures, but it was a damn sight closer than the original and subsequent ones. But you can't make too big a vehicle before it really just becomes a playset because it's too big to fly around (at least, for kids). I'd love the main "play-factor" action figures and vehicles be redone in 2" scale -- like Kenner's old M.A.S.K. line. With the advances since those toys back in the '80s, we can get all manner of detailing and posability into them -- at least as much as we're used to on the main 3-3/4" figures. Then the 3-3/4" figures can be the new superscaled Black Series stuff, with the really big vehicles to go with, and still retain some pick-it-up-and-go practicality. The 6" line needs to be just for figures and action accessories and some really small vehicles, like speeder bikes or the Phantom or like that.
The 2" scale would make it more practical to make playable vehicles in or close to the action figures' scale. Only really big ones, like the Falcon or U-Wing or Kylo's Command Shutle might need some scaling. 2" scale action figures are equivalent to 1:48. A 1:48 X-Wing is a bit shy of 11" long. 3-3/4" is equivalent to 1:18. A 1:18 X-Wing is over two feet long (27" and a bit). That might be cool and exciting for collectors and fans, but hard for a kid to maneuver. 2" seems the best balance between size, detailing, impressiveness... and compactness, storability, and ease of handling.
I also liked the smaller-scaled stuff -- articulated or not. I liked the larger scope I could get. But it wasn't the same, for me. In those cases, the vehicles became the characters for me, and the actual characters mere accessories. And the larger-scaled stuff has good novelty factor, but once we start getting past 6", the pick-it-up-and-play-with-it factor pretty much goes away. In almost every case I've seen, they end up being just display pieces. For that, I'd rather have a statuette or static figure model kit, that isn't marred by articulation joints and such.
As for favorites... Star Wars (including the Micro Series), G.I. Joe, M.A.S.K., Transformers, He-Man, Zoids, Starriors, Machinerobo/Go-Bots, Micro-Change (specifically the Gun Robos, back when that wasn't so politically incorrect)... And I also got turned on to Diaclone thanks to Transformers. I like the story, I like the piloted-mecha approach... It's a lot like M.A.S.K., except with the vehicles transforming into mecha instead of "combat modes".