My favorite is probably The Holy Mountain. I mean look at this shit how can you not love it
Worst movie is hard, because there are the "so bad its good" movies like The Room which is probably technically the worst movie I've ever seen but its also amazing.
So for worst movie I'll go with Jack & Jill (that Adam Sandler shitfest) and call it a day, although I don't really see the point in talking about terrible things