Powered armor! Starship Troopers, Armor, Halo, Alien, here we come!
As cool as mecha are, I can see past my irrational love of all things super robot to know that they’re incredibly infeasible (if you’re going to build a giant mechanized one-person fighting machine, best make it a Bolo); one hit to the legs and you’ll knock the damn things right over. A giant tank would be far more effective.
And as far as infantry goes, powered armor is the holy grail!
Glenn Reynolds tends to reserve this phrase for medical and life extension technology, but I think I speak for all SF fans when I say, “Faster, please!”