Bang+Buck = SP-808.: )

If you're just starting out, or a seasoned pro - you can't go wrong with a SP-808. If you know enough on how to sample beats on fruity loops, the 808's not too much worse. Plus, you get some way cool effects, mix capabilites, awesome built in 'virtual synth', vocoder, step modulator (do some trancy grooves with this and/or use it to control an effect knob or two?) and D-Beam. D-Beam's pretty funky for playing a 'theramin', abusing effects, or what I commonly do - slam my hand down on it while a sample plays to get that 'record stop' pitch effect. The only drawback with D-Beam and Vari-Pitch is there's no RAM in a 808. So you'd have to slam your hand on the D-Beam while recording to a DAT or PC and sample it back into the 808.

But if you're just 'starting out', I can't think of a better box for your creative future than the SP-808.
The majority of us here probably only use half the features on a daily basis, so don't feel bad if every song you do doesn't utilise everything.