I've spent a fair amount of time with the TR-8, and the new TR-8S looks even better. Elektron make some cool ones too, like the Analog RYTM. We're in the middle of a new golden age for hardware synths and drum machines right now.

This is the machine I have at home: http://mfberlin.de/en/device/tanzbar_en/

It's expensive and doesn't have the most intuitive controls, but sounds awesome.

Cheers
Kent