I like them all, with many of each.
I agree with the M/39 comment, they’re my favorite main battle rifle Mosins. Best sights, best overall design, beautiful birch stocks. The M28/76 is a cool post-WWII target rifle that is a great shooter with excellent ergonomics and sights, but not as steeped in history. The M91/30s are the cheapest and have that Russian WWII history allure, even after post-WWII refurbishment (99.9% of them). The short straight bolt handle and cock-on-open design on Mosins generally requires a slap to open technique.
I love the looks of the Mausers the most of the three. The build quality, especially on the peace time South American contract Mausers from Ludwig Loewe, DWM, and Mauser Oberndorf is amazing. Walnut! The bolts operate way more smoothly than the other cock-on-open design (Mosin). With the massive numbers of variations, I have more of these than anything else and I’m nowhere near getting them all.
I really like the peep sights on the No4 Mk1 Lee-Enfields. They are battle rifle sights, not target sights, i.e., large aperture for a good field of view. If you relax, focus on the front sight and let your eye naturally center the post, they’re very accurate. Bolts operate very smoothly once you become accustomed to the cock-on-close mechanics. Great British WWII history and better looking than the No1 MkIII in my subjective opinion. The No4 Mk2 is probably the best of all the LEs (excluding the T), but is post-WWII.