While browsers games are evolving towards more graphics intensive, cute, “social” games like Farmville; there are still a few hardcore oriented game developers who keep on saying “Graphics don’t mean nothing, game play is everything!”
Keeping in mind that this mentality also unleashed the horror of the Nintendo Wii upon our unsuspecting society, I urge you to carefully check out the latest browser based, multiplayer, zombie RPG. It is called Die2Nite and though it may look ugly to you if your idea of a browser based game is clicking on cute cows, once you get past the ugliness it seems to be really really good.
Die2Nite recently went out of semi-closed, invite-only beta and is now open to any person who wants to be eaten by zombies. It is here, and it is free.