Theres some really good looking trailers on the marketplace now,which were released yesterday due to this e3 event kicking off.
The best ones which i like the look of are left 4 dead 2,the long awaited splinter cell conviction, halo3 ODST gameplay trailer and a crackdown 2 trailer. O and of course modern warfare 2 but thats been out a little while longer.
I also found a new assassins creed 2 trailer which is not on the marketplace at this moment in time, which can be found
here