I guess I gotta get in on this. I've used many peeps over the years. Some aren't even made any more, but I still have them. I've kind of settled on the following:
Specialty Archer 1/4" Superball (hooded) with a #5 Verifier and 4X lens in an HHA sight. What I like about these is the versatility of being able to swap out different size apertures and/or lenses without having to remove the peep from the string.Those couple extra grains are not an issue as my main concern is being able to see the pin and what I'm aiming at.
I also like the 1.4" G5 but don't think they are worth the cost over a Fletcher of the same size. They're essentially the same thing, just that the G5 is magnesium whereas the Fletcher is aluminum. Either of these I would use on a hunting setup. From what I can tell I've got about the same results as Elkslayer 4x5.