I've got a Motif 8 which I'll never part with. It's a well rounded workstation with it's synth engine/sampler/sequencer arrangement. If you can afford it add a XV5050 or a XV3080. I use the 3080, and have a rather unlimited pallet and polyphony to go just about anywhere I want without restrictions.

Some of my stuff with this combo can be heard at: http://mp3.com/noisefuljoy