The Scorpion one and the Counter Strike one are both very nice, imo. I think that the Sub-Zero one lacks lighting and that the Protoss one is too plain. Good stuff.
New text, maybe some C4D and a new thingy IMO. And your signature is rather big. But #4 has potential. Maybe base your later tags off of that one?
I like how you display a whole bunch of different styles, I think this is the first step to be a good graphic artist (not designer )