You wouldn't recommend it

What's a video game you've put an absurd amount of hours into but would never recommend to someone else?

There aren't many games about which I could claim "absurd hours". But relatively speaking.

Marvel Super Hero Squad (I have PS2 version) is definitely not a good game. And while going through levels several times to unlock everything took some time, I may have spend more time messing around than actually playing.

The game has a sort of Smash/Brawl type mode for 2-4 characters to fight each other. The fun thing is that you don't have to play, you can just have CPU play each other to see who'll win. So I arranged great tournaments to see who are the best characters and spend lots of time just watching the game, instead of actually playing.

As fun as that is, it wasn't worth the pain of playing the game to unlock characters.
Btw, the clearly best character (CPU controlled) is The Thing.