Korg Electribe ER-1 by mtts
Picked one up because it was all I could afford in 1999, but still own it. It's that much fun.
The sequencer is awesome. Intuitive to use and allows all parameters to be automated - easily. The sound engine is, of course, digital and not very refined as you'd expect from something that was toy level cheap in 1999. The envelopes are limited, consisting of nothing more than a decay control and the knobs are so wobbly that you can pretty much forget about fine tuning anything.
That said, it does allow you to synthesize four different sounds per pattern and it gives you grittily sampled hi hats (personally I'm rather partial to the open hi-hat, but ymmv), a clap and a cymbal to boot that you can change the pitch and the decay of. If that isn't enough, you can sequence two separate audio inputs and if you want you can even ring modulate one of them with one of the synthesizers (you can also ring modulate two of the other synthesizers).
The synthesis engine isn't particularly deep, but it's good enough. It will not give you access to all the sounds you could possibly need (snares especially are rather lousy) but the kicks are good and if you're into gritty sounding digital clicks and bleeps, it will more than deliver.
A bread and butter drum computer this is not, but if you like something a bit odd and you can pick one up for a couple of hundred euros or less, it might be worth it. In recent years the ER-1 has become something of a cult classic with steadily rising prices. That, I'm afraid to say, is ridiculous. You will not use it enough to justify cult classic prices. It is, however, a very fun toy that can really liven up your arsenal of percussive sounds if you can find one for a reasonable price.