I own Marvel: Ultimate Alliance.
I really like the game but that is my own preference.
Honestly, it can seem to get rather repetitive after a while as it is the same hack and slash sort of game that you would expect.
The game has decent replay value if you want to mix up your team of Super Heroes and try a different setup.
I have not had the chance to try out the others yet. Heatseeker looks to be a fun game and I have heard really great things about the godfather.
Good luck in your decision if you are thinking of buying one of these titles.