Of the current production sights I like the Williams FP sight. I have them on eight rifles. Some needed a different front sight height, and some didn't. I'm using them on Winchester 94s, Marlin 336s, Savage 99s, and one 98 Mauser. Generally I've replaced the front sight even when not needed. The adjustments are repeatable, but I'm not sure if that is what the OP meant by easiest.