Pretty much anything other than stock. I've recently installed ACT FM1-SPSS kit, which included the pressure plate, clutch disk, alignment too, throwout bearing, and pilot bearing.
1. It's better than Centerforce, because it's rated to about the same power level (450 lbs of torque according to ACT), and it comes with all the stuff needed unlike Centerforce kit (no bearings, or tool included), for exactly the same money.
2. It's about half as light as a stock clutch, yet holds more power. It has to do with ACT specific pressure plate design, which has altered leverage points on the pressure plate fingers, making the pressure pedal way lighter.
On the side note, because the pressure plate design is different, the fingers don't come out as much towards the throwout bearing, so you might need to invest into an adjustable clutch cable. I already had one in the car, and I had to remove about an inch of slack by comparison to stock clutch pressure plate.