Continuity mistake: Jimmy gets ambushed. One gang member holds a gun close to Jimmy's face, but in the next shot the guy is way further away from him and not even visible in the shot when Jimmy gets splattered with blood.
Food Fight - S3-E2
Continuity mistake: At the start after Teddy steals Oscar's fries, he eats them, leaving his fork empty. The angle changes and suddenly there are plenty of fries on his fork.
Episode #1.8 - S1-E8
Continuity mistake: Towards the end, as everyone's gathering outside, Ken Marino has his hand in the front pocket of his shorts. The shot switches to a view from behind, and it's in his back pocket. Back to the front, and it's back where it was before. (00:22:10)
Continuity mistake: When Vaughn's assistant puts down the newspaper in front of him, it switches position to the left between shots. (00:38:20)