I see Y Tu Mama Tambien has been suggested already, but one movie I really liked was La Ultima Y Nos Vamos. It's rated very low, and it's probably only one of the few Spanish movies I've seen, but not too many Spanish movies can keep my attention. I will check out plenty of the ones suggested here because I'm very trusting of recommendations. The best part of watching Spanish movies is that being a film, you don't have to worry about the language barrier as the media is what keeps you hooked in. Don't get me wrong, I understand Spanish so my opinion might be a little biased.