Turtles for the NES was great!!
Worst game ever is possibly Ultraman for the SNES in my opinion, or as I call it, the game I shove in the back of my US adaptor
For this day and age however, I'd go for Red Steel, started badly, got worse, then got so bad it was funny, then I just threw my Wiimote because it was so poor!
Special mention to any Fifa game, Need for Speed Underground 2 and Test Drive Unlimited all for being incredibly overrated.