SeriousWB on 14 August 2008
Regnum Online, google it.
Nice timing as they have just released an English language based server (Original one was Spanish/International).
RvR combat, WASD controlled, you can't go wrong there.
Edit: And a contrast to all suggested thus far, there is a lvl cap on this game and the focus is PvP/wars.
Edit2: What's with all the MapleStory suggestions Dx Seriously people, try out Regnum.
Edit3: Here is a screenshot of a small fort war on the Spanish server.
