Personally I think the original The Producers was his best. No one can beat Zero Mostel, Gene Wilder, and Kenneth Mars in that movie. BUT, I will admit I had a complete obsession with Young Frankenstein. I was a teen when that movie came out and I walked around like an idiot quoting all the scenes. Puttin' on the Ritz is the best song and dance sequence in a movie next to SpringTime for Hitler IMHO, although Blazing Saddles Work scene (I Get No Kick From Champagne) is a very close runner up.