Try this game its a free fps that constantly updates with new weapons and maps every month and it even has zombies! which is pretty fun. the game mode is called infection and you have to infect other people if you are infected. If you're not infected you better run for your life! hahahah and the game has some good graphics for a free fps and it's called combat arms.
warrock.. not the best, but it is free
There is a really good online pool game at http://www.thepoolclub.com/
Though you say runescape as if you may be looking for an MMORPG(think that's what it is) I use to play one but quit, seems to me MMO's just keep charging money and money all the time either in game shop or monthly fee so I no longer play those. Though I am also looking for something new but this pool game was my very first online game I ever played, haven't played in a while but it was pretty good, way better then cheap stuff like yahoo pool (or at least several years ago)