I honestly can't tell you the right answer because for every person the best dancers are different. Right now, I'd have to say that most of the crews that have been on America's Best Dance Crew this season and even the legendary ones from the seasons before are some of the best dancers right now, but there are also other dancers on different shows like So You think You Can Dance, and Dancing With the Stars. I watch neither of those at the moment.
There are tons of styles of dance. My personal five favorite dancers right now are all from this season of ABDC, since I was pretty hooked this season: Raqi Carter from Jungle Boogie, Peter Veth, Jessenia Velasquez and Suzette Sagisi all from Static Noyze, and Lawrence from Poreotix. I just love their energy and their strength as dancers.
If you find a certain style of dance you like, look it up, whether it be hip hop, classical ballroom or jazz-- any style you like. I'd suggest you watch Dancing with the Stars because it features a wide variety of dance styles, and you can pick from the ones you like. :)