Quote (Zodijackyl @ Dec 7 2011 01:00pm)
There are quite a few good programs, there isn't a single "best" program. Most of them are plugins for recording software (i.e. ProTools), so you need a digital audio workstation (DAW) and a "host" program such as ProTools. Depending on this setup, you may also want to use a separate program to write/sequence the drum parts as MIDI files (a MIDI file is a set of instructions/written music that a virtual instrument can play).
There are countless drum softwares out there for various needs - a few that I am familiar with:
Toontrack makes a wide line of virtual drum softwares - Superior Drummer seems to be quite popular, and a lot of extreme metal guys use Drumkit From Hell.
Steven Slate Drums is also a quality program.
This.
DFH and SSD are the most used.