Zaino seems to be the consensus "best" polish because of the shine (it's not carnuba-it's polymer) on the forum with Meguiars NXT gaining a lot of fans.
Many detailers then put a several coats of a good carnuba wax over the polymer polish.
If you read through some of the posts in this forum and the Detailing FAQS, you'll pick up a lot of good info about not only waxes/polishes but techniques as well.
2004 E60 530is, Delivered 12/12/03, TiSilver/LGrey, PP, SP,PS, PDC, ACC, FRS, Step, Xenons, clear bra, body colored rear inserts. (Retired, 1983 henna red 320is)
2004 Corvette Z06 Commemorative Edition