It's hard to pick a "favorite". They're all beautiful in their own way.
Jeremy is spot on about the wrasses jumping tendency. I've got 11 wrasse in the tank and there isn't one day that doesn't go by where one of them isn't bouncing off the canopy/lighting like a pinball.
I've actually caught them in middair a number of times... when the canopy is open.
I do find that some wrasse over time learn that hitting the canopy hurts. As such, these wrasse rarely jump unless startled from directly below. The melanarus and exquisite never jump anymore as far I have observed. The flashers and lineatus though will launch with regularity.
Anyways, as to my favorites... I'm actually more partial to the flasher wrasses and colorful non-fairy/flasher wrasses as of late. Many of the fairies like the flame wrasse and most "blue" fairy wrasse require a small harem to achieve optimal coloration. With a tank my size I prefer packing it with smaller fish like the flashers as they are nearly as colorful and don't appear to be as territorial in general. I also like several Halichoeres wrasses. They are much bolder than the faeries and flashers and are as such always in the open. It's also nice that they don't require harems to achieve terminal male coloration either.
Honestly, you can't go wrong with a wrasse in your tank. They add vivid coloration, interesting movement, and lots of functionality. My problem is that I don't have the space to add them all!