I use a Two Bros. pipe and I love it. I've tried a few others, but this thing rocks. Excellent off idle snap, awesome mid range, and pulls strong all the way to the top. A great MX pipe. Large pipe diameter and excellent fit and finish.
FMF, White Bros R-4, and BBR (not Big Bore). Not happy with any of them. My friends and I have the same 88 motors and some have Sano, BBR big Bore, and White Bros. I like the responsiveness, sound, and performance from the Two Bros. Just my opinion, but might be worth the time to check them out.
another suggestion, wanna be really unique? build your own! it's a great learning experience, fabricating / calculating exhaust pipes (headers/mufflers) to bring out the top performance of your tuned engine.