Look, I can't stand Jack Black most of the time, and I can't really say that I'm much of a Mos Def fan either. But man, Be Kind Rewind is a wonderful movie that is completely worthy of your time. Mos Def is acually fantastic in it, playing a perfect Gondry character while making you wonder why he hasn't done something like this before, while Jack Black actually manages to be fairly funny throughout most the movie's run time.
The film lacks the strange, psychedelic brush strokes and heavy subject matter of Gondry's two previous films, but it'll still make you tear up a little, which is awesome because it's a perfect date movie and girls like emotions and stuff. Seriously, don't believe the so-so reviews. It's completely worth it, and the original soundtrack is fantastic as well. One of the few times I can honestly say "I left the theater with a smile on my face" like all those lamos who review movies for a living.