For me? Err...the best game for me is Minecraft. Regardless of the graphics, it doesn't have any whiny kids with behavior issues most of the time with people saying "Pwnt" every time they kill someone in game (and yes, I'm talking about ROBLOX). It has epic monsters whether it's a creeper, a zombie, or a spider. It's very simple to make your own server, it's got everything.
ROBLOX. After about a year, things started to get even worse. Every time you'd enter a game, the server would be infested with noobs, exploiters, liars, and crappy admins. There's whiny little 6 year olds with sucky grammar and behavior issues. The theme today is f**ked up and hard to use, unlike 2008, where it was epic. The graphics are decent, but they were much better in 2008, but lets not get started on that, as I don't judge games by the graphics. There's trolls, and people who say crap like "ZUMGZ!! CRAZEE GLICH AT MAH PL@C3!!!1!!!!1111one!!11" and "ur my new gf from now on, <3". It's just a disgrace, what with lazy admins who just sit on their lazy butts trying to find what old hats to put on the front page. They used to have great ideas for the players, they used to try to stop exploiters, they used to stay active and care for the community. But now the game went totally downhill.
What's your best and worst game YOU played?