They're both awesome but very different. If you have to pick one, ask yourself what you like more...

If you like taking cover, planning a strategy and utilizing a squad, go Vegas 2.

If you prefer a faster-paced, arcade style of play and vehicles, go with Bad Company.

I love both, but at this point if I had to recommend one I would go with Bad Company, by a hair.

Film grain? Looks bad, way overdone. The sky looks like static, not stylistic film grain. Still, you won't notice it too much as you're blasting foos