Yamaha Motif fully loaded with a huge sample library, no doubt about it.
And if not the Motif then one of these with a huge sample library:
1. Korg Triton Studio
2. Kurzweil K2600
3. Yamaha EX7
4. Roland MC-909 (although I've never seen one in action).
5. Korg Karma (doesn't sample, but still a very cool board).
Stretching synth a little, but everything comes off s5000. apart from that waldorf Rack attack is really cool. does really good Drums and basses. need to be layered with samples though!
or any of the big boards from Korg Yamaha Kurzweil or Roland. With these you get a wealth of sounds, sampling, and sequncing (i'm not a fan of sequencing on my board except for dropping down ideas).
Alot peeps mention the mpc which i own one and love but it isn't cheap and you get no sounds with it. The boards can perform similar functions as the mpc until or if you decide to get one.