I own Crysis 2 great game. I plan on checking out Metro and Singularity this weekend.
I beat Singularity in a 2 sittings. Good gameplay, not enough UMPH imo
If you like fast games like that I would go with BulletStorm. Its cheap now and has a decent replay value.
But long term, I'd go with a MOH series, Borderlands 2, or Metro