This is something of a heretical view, but I have to admit that I find the Orcs and Fighting Urukhai(FU)[sp?] far more impressive than the Nazgul:
*The Orcs laid waist to the forests around Isengard
*The FU captured Merri and Pipin
*The FU killed Boromir, greatest warrior of Gondor
*The Orcs and FU together virtually destroyed Helmsdeep, nearly gutted the Rohinim, and definately filleted and army of Elves
*The Orcs nearly captured Middle Earth's greatest city, Minas Tirith, and were only destroyed by a combination of the Rohinim and an army of ghost-warriors
The Nazgul?
*Couldn't find four Hobbits outside the Shire
*Managed to viciously kill four pillows
*Could only manage to stab Frodo - once
*Got smeared all over a riverbed by a single Elfin woman
*Had their leader completely miss Frodo and Sam - as the scaled a sheer cliff in front of his palace
*Said leader later got smeared by one shrimpy little Rohan girl
GO ORCS!