Best? Depends on what you're wanting to do. There are lots of bolts out there for consideration. The Shocktech Superfly and AKA lightning bolt are the most common and respected, and they work well in terms of lowering your pressure and sliding slickly. I personally use the Superfly in mine and see no reason why I should switch to anything else. There are the DYE twistlock and Shocktech Chris Cole bolts which eliminate the pull pin and come matched with their own backblocks: the DYE has a knob, and the Chris Cole neatly screws into a thin, flat block with no hole in it at all for a nice and clean profile. Of those two, I think the Chris Cole looks the best, but that's your call. Any of these 4 will add style to your gun and increase the resale value.