I don't think anyone's actually making a decent hardware drum machine these days; that is, one that's easy to program, has good sounds and professional features like individual outs, which you NEED for serious recording.
The Boss DR-880 is the one machine left that has individual outs, but I've always found Boss machines difficult to program at best and an utter nightmare at worst.
The Roland R8 mkII, from the early 90's, is probably the perfect drum machine. Tons of great sounds, extensive editing features, individual outs, easy to program. The original R8 is also an excellent choice; it just has far fewer built in sounds than the mkII.
Currently, my workhorse is a heavily customized
Oberheim DMX. It doesn't sound anything close to a real drummer, but it sounds so fantastic that I don't even care. I also use
my LinnDrum a lot these days. These machines may be dinosaurs compared to even an Alesis SR16, but nothing sounds quite like them and in terms of punch, they're unbeatable. (especially the DMX!)