The Everyman's Drum Software
I'm a convert from Superior Drummer and though Superior offers a million samples per drum with full tails on them, you really need to know how to mix drums to make it work in a mix (IE adding effects and filters to each tack and then EQing). With SSD4, everything is pre mixed and sits perfectly in any mix with one or two volume tweaks for your main group volumes such as toms, cymbals, kick and snare. With layering different kicks and snares you can also achieve almost any sound you can think of with the software, and thanks to it's small install footprint you'll have plenty of HD space left to actually record.
The only (very) minor negatives I can think of are that as of right now, the midi groove library is still a little on the small side, cymbal chokes need a little work and they could have a slightly larger selection of cymbals.
All and all; the price is fantastic, the samples sit perfectly in a mix, the interface is really user friendly and you'll be hard pressed to find a music type that this software will not work with.