I think the old saying still applies here - shoot what you shoot best. I've killed several freezers worth of antelope with my trusty 30.06 - mostly with 165 gr bullets. I'm generally a one-gun kind of guy - it's worked on everything from antelope to moose. However, between me and me kids we've also used a .243, a .270, and a 25.06 to kill a bunch. The only (slight) negative is that these smaller calibers can have a problem with wind drift - and the wind is always blowing where we hunt pronghorn on the high prairies of Wyoming.
Ahhh, that reminds me of my very windy hometown, Great Falls, MT. The joke when I was growing up was that one day the wind quit blowing....and everyone fell over.
Every antelope I've killed has been with my Savage lightweight hunter in 260, nice light weight rifle, very manageable recoil ...................... BTW my lifetime total on antelope is 'one' so you can toss my opinion if you want, but I do really like my 260.
Since no one has mentioned it yet..... I'd have to say the .25-06 is probably ideal. Although you could go .257 Roberts if you want to be a little more unique and have similar ballistics. 100 grain Barnes TTSX should be ideal.