I've never played a DMD, but hey why should that stop me offering an opinion    I've got a couple of SSs and a couple of EMs.

For the same reason as others, that being what I grew up with, SS from the late 70's, early 80's do it for me. The speed of them is good the rule set easy enough to understand and play to, yet complex enough to be hard to master. Cool sounds - continuous and speech - for what an electronic pin should sound like to me. So if I was only allowed one species, it would be SS.

I like EMs for a different reason, they represent more of the history and make a great racket when played. There's nothing subtle about a chime box bashing away, it's also cool technology and ingenuity for the time, but the ones I've played have a much shallower rules and play a bit slower. The art work is also more innocent and simple - in a busty babe sort of way.