Here's a concept I literally just came up with to generate some more discussion. For fun!
It's really easy. There's a given line (Cybertron, we'll start with, because a lot of us liked Cybertron) and we all post one figure we liked, and one we hated, and some brief reasons why--not a whole review, just a blurb. Then we can all react on those that other people posted, and keep posting new ones as we go along.
I'll start!
Loved: Megaloplex (Metroplex/Megalo Convoy). A huge robot! His colours could've used more red and his face could've been painted so he was Moar Metroplexxy, but in general he's a pretty cool update in his robot mode. His altmode could definitely have been executed better, though, especially for what it was trying to be--but I feel like that doesn't drag the figure down too much since he's primarily a Hugeass Robot. I'd recommend getting him secondhand or sealed if you can find him cheap.
Hated: Thundercracker/Skywarp. I only got Skywarp--I think because I didn't have the mould and he was cheap at the time, or something. He promptly broke during his first transformation. I often say that there's only one TF I fully regret owning; Energon Megatron, but that's not true--I also regret CybWarp. I think he's the only mould 86 and I have *both* broke while getting him out of the package. In different places!