From Zynga's Mafia Wars(TM) comes this official "It's not personal. It's Business" shirt featuring gun, knife and the official logo. Find more of their official gear here. Each shirt can be cutomized so you can even add your username to encourage more people to join your family!
In salute to the ever popular Farmville(TM) is this super cute "I'd rather be farming" shirt. We're not sure if the product is officially liscensed but we really like it.
Pet Society(TM) has tonnes of really cute and cuddly pets and a whole range of official gear like this sweet Marilyn shirt.
Pet Society Woman Marilyn t-shirt
Pet Society comes from Playfish who also bring us Restaurant City™,
This generalized gamer t-shirt plays on the evolution of man.
Another general gamer's shirt, this time a rather cheeky one.
The mantra of so many .... Eat, sleep, game!
Every gamer knows these symbols only too well!
Atari may be the Grandaddy of gaming but they're still going strong. Here's one of their official shirts for Crystal Castles(TM) featuring Bentley Bear.
Official Medal of Honor shirt, more gear can be found here.
Cute "Powered UP" shirt from Megaman(TM) by Capcom(TM). Click the names for more merch.