I prefer games that don't take themselves so seriously (insert Joker image)
NMH is a game that certainly doesn't take itself seriously, and this trailer takes that to a new level (random images of Safari animals being an example)
I am pretty sure I would enjoy Mass Effect 2 a lot, Mass Effect being one of the few X360 games that interests me. But this trailer is taking the game even more seriously than the game probably does.
Just a personal preference, and they both clearly work as trailers for their audiences.... No More Heroes trailer emphasising the random and non-coherant nature of the game, and Mass Effect trailer essentially trying to be as "epic" as possible.