I played the demo for Bulletstorm, it was alright. It reminds me of Gears of War. I think the only reason I would pick it up when it first comes out is for the Gears 3 beta and I definitely don't want the beta that badly.
I'm with Peter on that, I would rather a game with a good plot than the ability to shoot someone in the balls.
Okay I've been away for a couple of days - old games (like Doom) had a plot and story but nothing you did along the way changed the story or plot - most old games were like that as they didn't have the storage capacity for multiple stories.
Typically you're god-modded into "you will kill this, you will say that and this will be the outcome". And that's it - only the current gen has really had the multiple scenario, story and ending as there's a larger storage media to work with.
Some older gen games had multiple endings but these were usually done via pressing a button at the end screen (or just before) and not guided by actions within the game although there were a handful which were.
I think that's pretty much covered all that bit
Now I'm just waiting for the release of the MadCatz amBX to see how good they really are for myself
I generally pick things up after reading about them and by things that i'm interested in.
I no longer rent games because there isnt a need to since finding info is so simple now, just watch some videos read up on its game mechanics and go from there. Plus a lot of games have a demo or trial ^^;