Wuffenloaf - S3-E1
Plot hole: When Abby and Eric return the night vision goggles, Abby asks if they should put them back exactly where they were and Eric says he didn't remember where they went but luckily he "took a picture" of how it looked before. How could this be possible if Abby purposely excluded him when she collected those goggles from Lisa?
Jiu-Jitsu, Bubble Wrap, and Yoo-Hoo - S1-E17
Plot hole: Near the start we see Sheldon using physics to try and take down Tam. This completely goes against all of Sheldon's phobias about touching people, especially socks. Even before this episode he has shown his displeasure at the thought of touching people. (00:05:00)