I'm not the best person to engage in a discussion of "sharpest" as I don't value sharpness above all else. To me all of your photos are acceptably sharp. Each lens that you own is capable of producing acceptably sharp photos, but they're not "the sharpest" lenses.
In the past 5 plus years I've used over 15 different Nikon lenses - zoomes, primes, autofocus, and manual focus. All but one were acceptably sharp. The exception was the 70-300D ED, and then only shot wide open in the 250mm plus range. Otherwise it was plenty sharp for my purposes. I usually don't pixel peep or print enlargments greater than 11x14.
Generally I would tell you that primes (especially micro primes) are sharper than zooms, and pro quality zooms (f/2.8) are sharper than variable aperture consumer zooms. But certain lenses are exceptions and don't follow this pattern.
My sharpest lens? Probably a toss up among several. The contenders are Ai-s 50 f/1.8, Ai 105 f/2.5, AF 180 f/2.8, AF-S 80-200 f/2.8, and Ai 75-150 f/3.5.
Cost is not always indicative of sharpness. The 50 cost me $45, not much less than the 75-150 at $65. Both are very sharp, but not the holy grail of sharp lenses. I doubt that any lens I own would ever make a top 10 list of the ultimate sharp lens hall of fame.