Don't play Serious Sam 3 on serious difficulty. Seriously. Unless you like pounding nails into your dick. Play it on normal though, and it's awesome fun and it'll still put hairs on your chest. Though I heard that the first few levels are ass, and it gets good after stage 3 or 4, so I might stick with the difficulty setting for now.
One of the reasons I love the Halo games is that they are still fun on the hardest difficulty settings. I don't know many other games that can do that, where it just whittles down into an exercise of frustration for me.
I need to go get my copy of Anniversary already, really wanna beat it on legendary.