Possibly the best selector switch on the market today - Badger Ordnance Condition 1 Modular Ambidextrous AR Safety Selector

This selector switch is set up exactly how every switch should be. The 60 degree throw is perfect, not as awkward to actuate as a traditional 90 degree throw but not uncomfortably short like the 45 degree throw many other brands use, the short weak side lever is just short enough to stay out of the way of your hand while still being long enough to be flipped with ease, the red tip makes it easy to tell what your rifle is set to without needing to actually look down at it, it looks great, the installation method is very solid and there's no risk of a screw coming loose or it being knocked out of the lower, and its made using quality materials. I'ts not cheap but you are getting what you pay for.