You honestly cannot go wrong with any of the upper-end recommendations that have been mentioned thus far. All you are going to get at this point are repeats of everyone's particular favorite, whatever that may be. The things that really differentiate the performance of the optic are (IMHO) the glass quality and the reticle. Decide on those, and you will have your answer. Your best bet, in lieu of being able to examine each of the optics on your short-list, is a phone consult with Omer at Precision Optics, Tom at Go Big Tactical, or Peter at Hirsch Precision. Any of those gentlemen ought to be able to provide you with a run-down of the scopes in question and should be able to answer any questions that you may have. You are paying for customer service, so you may as well get some up-front by picking the brains of your vendors.
I've had the Vortex Razor HD Gen 2 4.5-27x 56, the Leupold Mk 5 5-25x 50, and the Nightforce ATACR 7-35x 56. All are excellent in their own right, with each having specific design features that may appeal (or not). The Zero Compromise, Tangent Theta and Sxhmidt and Bender are a step up to the top-tier of rifle optics, which may be overkill for your purposes. Yes, it is always nice to have the "best" of anything, and additionial capacity (or magnification) is always welcome. But at the end of the day, you end up paying exorbiant cost for minimal gain when you are talking about the bleeding edge of optical performance. Sometimes the juice just isn't worth the squeeze, and "almost the best" is plenty good enough. I would stick with the flagship scopes from each of the "second-tier" manufacturers - Vortex, Leupold and Nightforce being the names that immediately spring to mind...