depends on how you define the best. eotech makes the best of the open top red dots where as aimpoint is the best of the closed tube models. open tops obstruct less view but if the diode is dirty you wont get a clean image. closed tubes are much tougher but obstruct ALOT of the view. i have only really used burris speed bead and the bushnell holosight. both were ok but after a while they both seemed to flicker after every shot.