My wife likes the Disturbed version of Simon and Garfunkel better too. I prefer the original. I think the original was a demonstration of how powerful folk music can be.

One cover you don't have listed that I like better than the original is Santana's cover of the Zombies "She's not there". I love, love, love the Zombies, but Santana took an already great song and added Latin-Jazz goodness to really make it their own.