Zero Online
Giant Robot MMO with designs influenced by everything from Gundam to Transformers. (You can even transform later units)
Good game so far and in Beta. Down side is huge PvP once you get past lvl 120. (might be lvl 100, I forget) You "Evolve" your robots at various levels. Your first evolution is at lvl 20-something.
Your choice between ranged unit or melee, there are tons of types of weapons from Flame throwers to scyths.
Getting yourself Zero points and purchasing a badge will make things alot easier on you. (More exp, pvp curses for those that kill you, offline leveling, etc)
The game is a pain in terms of financing...everything costs out the ass. Especially the Guild of mine...yeesh. Though lots of cool options including marriage and such.
I recommend this game to fellow mecha lovers. XD
Note: The game is over 1 gig, so expect to be downloading this bad boy over night.