I own a 6mm, .270, 30-06, 7 Mag, and a .338 Mag. Out of all those, my 7 Mag outperforms them up and down. It's a custom Winchester Model 70 with my own bells and whistles, but it shoots quarter size groups at 400 no problem with 160 gr Accubonds. While it has significantly more recoil than any of the others mentioned, once you get over the flinch factor, it's smooth sailing. I can put 25-30 rounds out of it before I notice any discomfort. When before, it was about 8-10 rounds.
So for an all-around popular caliber, the 7 Mag has to be at the top of the list. .300 Mag's are nice at times too. But I've come to find that .300 WSM is a waste. Again, these are all personal preferences, but with the range of grain configurations, the 7 is a good choice. If you don't like recoil, consider a thicker pad, or a muzzle break and lower grain bullets in the 130-150 range.