Are there any good hip hop beat making programs out there that are easy to use, and can be downloaded off the internet and is free?

Im looking for something like GarageBand for the Mac,

I tried Fruity Loops or whateva its called, but it was extremely confusing, I need something simple, but with a lot of different sounds.

Whats the best one out there that is Free and lets you use alot of feautres? and is simple to understand.