A Perfect Circle - The Package (good bass line and good song)
A Perfect Circle - Lullaby (Weird song, but just turn it up and make sure you're sub is on lol...have fun

)
Chris Jones - Long After You're Gone (great song, great instrument separation and deep bass)
Nine Inch Nails - Discipline, Corona Radiata, & The Four Of Us Are Dying (deep bass in all of them)
Korn - Did My Time (there's quite a few Korn songs that will give most setups a workout)
A Perfect Circle - The Noose (at 1:50...turn it UP!! If you have little distortion and the ability to get loud without sounding harsh this sounds awesome; not really a 'bass' song, but it's fantastic)
I can add more later if you'd like