Best piloted robot games?

Though question is obvious, I'd like to ask you: by the way, do you like Gundam? Which game gives you the best sense of being piloting a gundam?

The focus here are Steam games, but you can mention any game from any platform (please tell which one), gundam-ish or not.

For whoever who doesn't know which is Gundam, it's a Japanese animation franchise where giant piloted robots called gundams battle on Earth, sky and space against other giant robots, piloted or not, using all sorts of firearms and, sometimes, lightsabers (the plots are often complex, heavily based on political issues which lead to dramatic wars, but the game doesn't need to have a plot like that to make you feel like being in a gundam). If you know any good game like that, please tell. The robots don't need to be giant too.

For example, one of the games that made me feel like piloting a gundam was Metal Warriors from SNES, where you could pilot different robots, control the pilot to change robots and fight with your robot on the floor and on the air (there were some spatial environments as well, but it's not required to make it feel like "gundam-ish").