the parmakit, vm20, 2 petal, tecno estoril is my favorite. great power throughout the entire rev range. 55 mph all day with tall gearing. good packaging, easy to tune. the porting on it is so much better than the cheap alukit 45mm kits with nice split transfers and booster ports. they look similar but look close and they are totally different and way better.
i haven't checked out the new Dos cycles clutch shoes yet but a few people have posted on here that they are the way to go.