Well... if you truly want something free that CAN do quite a bit. but does require some work, then check out the "Hammerhead Rythm Station."
There are lots of additional plug-in sounds available and you can make a decent drum loop or more with it, which can be saved as a WAV and imported into your favorite digital recording software.
It's FREE!!
http://www.threechords.com/hammerhead/Check it out...
John