I would have to say which no one hasn't said yet is Guitar Hero 3's credit song. For those that are stuck in a hole and don't know what it is it is Through the Fire and Flames. Oh Here Speaking of Guitar Hero 3- http://www.youtube.com/watch?v=54iENpd6BwM
well im a big fan of orchestra music (and 80s rock), so i loved the halo 3 music ending. but for me, portal takes the cake, wait! the cake is a lie?!!? NOOOOO!!!!
Nothing's more epic than GH3 after you completed it for the first time with your guy on that huge podium playing in hell or wherever whilst rocking to Through The Fire And Flames, i got a buzz playing that lol. Also, Portal was so funny i had to use the toilet
http://www.youtube.com/watch?v=u9zZus_1_ag&feature=related Live and Learn - Sonic Adventure Battle 2.
yes i thought allot of people would say portal - still alive but there are other great ones that don't get the credit hey deserve so here's a good list: Assassins creed - http://www.youtube.com/watch?v=XOrDRVwBMP4 epic, good tune and goes well, not the best but very nice that's all i can think of at the moment but i know there's many more.