The Triton is probably the best all around Workstation available. The sounds are just remarkable, and has the best drums sounds on a keyboard that I have ever heard. Plus it offers sampling and sequenceing. You can't beat that.
Yamaha has new workstaion coming out, which offers pretty much what the Trion offers, can't remember what it's called but seems to be a contender. Also Roland has their Fantom workstation which is also a strong contender, although I'm not sure if it offers sampling.