Uh, not that it matters what I think, but I personally hate when trailers like the Mad World Gears of War trailer, and the Dante's Inferno (Aint No sunshine when shes gone) trailer come out.
It's a bad ass bloody game, its dark, its violent, but oh look its got a melodic soft and beautiful song. How touching, how artful, how deep.
I find it insulting. Yet I see people on forums eat it up, use it as arguments that games should be considered art. If you want to show that games should be considered art, go find some artful gameplay (Theres plenty of it, imo). Don't play some soft 90's emo rock song over a bad ass trailer and call it beautiful, it totally doesn't fit. And not in a cool clashing best of both worlds kind of way. Just a weird, awkward, silly kind of way.
It reminds me of what I used to see on youtube in 4th grade when people would take their favorite song and put it over some completely conflicting image on youtube and call it a "music video". I've seen more Kingdom Hearts/The Fray mash ups than any human should ever have to be subjected to.
My favorite trailers are like the ones for the upcoming Dark Souls, and the Legend of Zelda e3 trailers. (The Twilight Princess reveal was the most epic thing ever). Stuff that will get you pumped for a reason. That stuff is awesome.