Undeniably the best - Radian Weapons Talon-GI 45/90 Safety Selector for AR15

I use these on every gun I can. They snap back and forth between positions perfectly, and the 45° throw is so much more natural than 90°. Also, the switch itself is attached to the barrel in a way that it cannot loosen, which is not the case with most other selectors. You will never want to use anything else. Radian Talon is as good as it gets!