My favorite is still the "old school" PMII 5-25[56] 0.1 MIL CCW with Gen 2 XR. Environmental conditions allowing, the Gen 2 XR's .075"/100 yard line width subtension means a line width of .750"/1000 yards, allowing "quartering" 1/2 MOA targets!
My 22" barrel X-Ray 51 & 26" barrel X-Ray 66 both...