There are many games like halo. Try section 8: prejudice on the xbox live marketplace, or as someone else said, singularity. Crysis and the newer Crysis 2 are very halo like, complete with regenerating armour and a super suit with fast movement and high jumps.
Section 8: Prejudice for the Xbox 360 Arcade, PC, and I believe the PS3 (I could be wrong on the PS3 part, sorry) is pretty similar. In fact, the graphics reminded me straight up of Halo. It even has a good co-op campaign for you and your buddies.