Gazzo's is amazing. Palmer's is amazing. And The Penultimate Cups and Balls was the first complete C&B routine I ever learned (thank you to whomever worked at Hank Lee's in Boston who sold it to my dad)

I think the two cups routine that Tommy Wonder does is the most beautiful and the most amazing one.

Shawn Farguhar's is the best I've seen with 3 cups
David Regal's is great as well.

With two cups, gotta go with Tim Ellis' milk shakers... Fantastic!
But David Williamson's two cup routine is a close second, and more practical for most magicians.

With one cup... I've only read about them, but John Carney's Benson Bowl routine looks good, as does Larry Jennings.

(IF you want to count Chop Cups, the original Don Alan routine still kills laymen!)