Obviously, this is all a matter of opinion but here are my thoughts on the ones that I've purchased: Iron Man is the best of the three. He has a strong alt mode and the robot mode is also very well done. Venom has a great alt mode. That is one of the most badass cars I've seen in a Transformer of any type. His robot mode is absolute garbage. Hulk has a weak alt mode and his robot mode is kind of meh. Just my
I think Hulk and Spiderman are the best. Venom has got a lot of car kibble and Ironman just looks kinda lame and has gimpy wrists.
Hulk is the best but they've all got their share of problems. In Hulk's case, his altmode is rather unconvincing, his face looks goofy, and he doesn't really have waist articulation because his punchy gimmick makes his waist spring back to neutral position. But his transformation is unique, and out of all the Transformers with punchy gimmicks, his works the best.
In order: 1. Venom Great vehicle mode and I dig the robot mode. Transformation is quite good, although sometimes it's frustrating 2. Wolverine Both good vehicle mode and robot mode. Love the pop out claw. Would be better if it's 3 piece instead of one 3. Spider-Man Both mode are good. It's just that the color ruins the bike mode for most of the people. Black version will be a lot better 4. Iron-Man A...kiddy jet, not that bad. Robot mode is nice, except the leg joints cause some funny poses 5. Hulk I don't know why so many people love him. He's just meh. Loose vehicle mode, a just ok robot mode
From what I've seen, Hulk and Iron Man are the 2 best so far, with Spidey and Venom being the weaker of the lot.