I can't do my favourite, but I can do top 3
1. If you can't take the heat, get out of the rocket propulsion test chamber!"
2. "No, your other hand you idiot!"
3. "As I expected" "What was that?! You trying to say something about me?! Man I'll kill you... prick"
That last one was what got me hooked on the whole series. I was literally rofl