Not a single player game, but still an awesome Mech game is Hawken. [1] Ever since I first tried it other FPS games seem pretty boring, I can't go back to playing Battlefield or Call of Duty after the spectacle of Mech fights.

If you decide to try it, my nickname is 'shadelesss' ;)

[1] https://www.playhawken.com/home

Most recently, Titanfall.

As someone who considers MechWarrior 2 to be one of the finest games ever made... Titanfall is amazing, and scratches the blow-things-up-in-an-OP-mech itch well enough!

It didn't do it for me, but it did light a candle :)

It's missing the tactics that I loved from MW2 (and the world and lore), but I also love fluid fast-paced first person shooters, so for me it's perfect. One of the best multiplayer FPS's for myself since the original Unreal Tournament.