I own a 7mm-08, 30-06, 22-250 and .308 (haven't fired it yet)
My favorites and why.....
7mm-08 because it is a bit smaller than .308, a bit flatter shooting and has forced me to reload, and most importantnly, I wanted something different than the more common calibers.
22-250 because I could shoot a coyote in the eye at 100 yds! Mind you I still get excited when I squeeze the trigger, so not quite ready to try this!
30-30.... I don't own one right now, but I have and they are just cool.
If I ever make it on a Moose hunt, I might add 30-06 to that list, mind you the 7mm-08 should suffice.