MSM mounts.
http://www.miataroadster.com/mazda/m.../i-465886.aspx
From what I've read they are stiffer than normal NA and NB mounts, but less so than Mazda Comp. mounts. I have them in my NA, and considering my stock mounts were both ripped in half, they're a vast improvement. Shifting has improved as well A friend who has had multiple NAs & NBs, along with having driven several more, commented on it being the best feeling 5-spd he's felt. Which is impressive considering my car's mileage (178k).
Same friend installed Mazda Comp. mounts in his 10AE and while the initial impression was great, he started to notice vibrations the car didn't have before, mostly at idle.
Not a fan of knockoffs... granted I run Chaparrals, so... yeah. Then again, everyone makes a copy/replica/knockoff of the original Minilites, and it's a little different since Minilites are only available in particular sizes/offsets. Anyways, after a troublesome clutch job thanks to an OBX header on another fellow's car, I hate those specifically.