Okay about that scene in Pulp Fiction when Jules accidentally shoots Melvin in the face…the boyfriend CRACKED UP at that part and I didn’t find it funny (or offensive for that matter, just kind of odd and unexpected) and I kinda worried about him there for a couple minutes. So I guess he’s normal! 
As for me, I don’t feel guilty for laughing at anything. I like Family Guy, Mallrats, MXC, Larry the Cable Guy and all that good stuff. The only thing I feel guilty laughing about is when people fall down. Because when someone falls down in real life I laugh even harder than if someone falls down on TV. I don’t care what anyone says, people tripping or falling is the funniest thing ever.