Re: Giant robots! Another meme too cool for its own good.
I can think of environments in which giant mecha would be superior to UAVs and other armed vehicles. Unfortunately, they're pretty unusual--high gravity, low atmosphere, extremely rough terrain. The terrain would have to be rough enough to basically require climbing and jumping, and the gravity/atmosphere combination has to be difficult enough to prevent effective UAV usage. Otherwise you're better off just building a tank like everyone else.