I've played a bit of Knight Online, and it's not too bad. It's a MMORPG, free to download and free to play (though there are some perks you can buy). It's basically like every other fantasy MMORPG, but stripped to the core. Go out, fight, get stuff, sell stuff, buy better stuff, go out, fight... but it does try to encourage players to join parties of others in order to level up faster.
It's interesting, and pretty fun.
http://www.knightonlineworld.com/ C.