Shockwave is my favorite, I had that comic: Transformers ...ARE ALL DEAD.
I have collected them on and off, but somehow have managed self-control and not spent a lot recently. I think the only Masterpiece figure I have is Wheeljack, but I obviously wish I had them all. Prowl would be the next one I'd want, the price dissuades me somewhat, I guess its just high enough for my very limited self-control to manifest.
There was a line a number of years ago where they had Transformers that transformed into modern cars, I think I have a Silverstreak that transformed into a Subaru and a really nice Hound from that line, but I'm not sure where I misplaced them since my last move.
I think if I collected as much as I wanted, I would be happy with them, but poorer. My collecting money has been funneled into more of a Star Trek direction, for the most part. I would be all-or-nothing and my bank account is happy with the "nothing" but I yearn for more ridiculous toys.