There are built in ones, but I want something realistic sounding to go with my (real) guitars and bass.

EDIT: Not sure why you deleted your response, as you made some valid comments, so I’ll just write my response here: Free synths are usually OKish if used properly. But I’m not looking for OKish, I need something that sounds as good as the real thing, and for that I am willing to pay.

Last time around I used pirated stuff. Cakewalk Sonar (although I didn’t like the newer versions), Drumkit From Hell, and misc Edirol stuff mostly focusing on piano and orchestra. After really enjoying a trial version of Bitwig, I’ve decided to go for the full version as the foundation, so now I just need to find modern equivalents to the rest so I can buy them.