I have several:
Plextor 12x10x32-Very stable! I made several coaster initially but thats because of termination problems which have been rectified.
HP 9340i 10x4x32-Very stable also, has 4 meg buffer which helps a lot, no burn-proof though. Never made a coaster!
Richoh 7040 4x4x24-Even though it is slow this puppy NEVER made a coaster!
HP 7200 2x2x6-Slow as hell but never made a coaster!
Philips Omniwriter 2600 2x2x6-Second rewritable drive ever! Slow as hell, made TONS of coaster initially with HYCD utility (which sucks big time!). But hey, its an external scsi and I only use it with my laptop!
The Plextor is my favorite and most stable(for obvious reasons) but the HP 9340i is a very close second!