As others have said, I like them all, but some more than others.
The 7mm Mag has so much case capacity and muzzle velocity that the cartridge is pretty much committed to premium bullets for hunting unless the target is beyond about 100 yards.
I've never been too fond of the 22 WMR. If I need something more zippy that 22 LR, I can shoot handloaded 223 for about the same price as 22 WMR.
Never warmed much to the 40. More expensive and less fun to shoot than 9mm, and probably not as effective as 45.
8x57 is a effective round, and powerful, but not quite as nicely balanced as the 30-06. I never had an 8x57 that was very accurate, and I didn't need the cartridge for anything in particular, so I've gotten rid of the old Mausers.
I have no quarrel with those who have and love these cartridges. I just don't like them as well as some others.
On the plus side of the ledger, my el cheapo bolt action 30-30 is a blast to shoot, using GC cast lead. 38/357 is great fun in a lever action carbine. 7x57 loaded to modern pressures is an outstanding and versatile all-around hunting round. 6.5x55 loaded to modern pressures is a great long-range round. No offense to 270 lovers, but we might have been better off adopting 6.5x55 than inventing 270.