My all-time favourite piece of studio equipment is, by far, the EMU SP-1200, It's a low-res 12-bit, nasty sampling drum machine. Because of limited sample time (only 10 seconds), it forces producers to be as economical and creative as possible. Launched in 1987, it quickly became the definitive sound of hip-hop during the late 80's and much of the 90's. Of course, it's pretty much obsolete by now as far as memory and technology goes, but still- the sound of the SP1200 cannot be beat.
Here's a video of the beast at the heart of Ski Beatz's studio, with appropriately melodramatic intro music:
All of my favourite hip-hop producers used this and a lot of New York house DJs and producers (like Kenny Dope and Todd Terry) relied on the SP-1200 for dirty, crunchy beats. As budding producers, my brother Terry and I just had to have one. We got ours about 12 years ago, and to this day it's impossible to make drums sound as good as they do on the 1200. Gritty sounds and perfect swing, I could hit those pads for hours :)
I actually just found out this year is the 20th year anniversary of the SP1200, which kind of amazes me. I can't believe it's been so long.
Happy Anniversary beloved SP.