I have no favorite, but I do have opinions...
The 30-30 is a great cartridge, but the case is awfully tapered, and has a capacity just a hair low. Great for cast bullets, so-so for jacketed bullets. The old Krag case is great, but once again, though the capacity is excellent, the case is tapered too much. It also works great with cast bullets. The 300 Savage has an excellent capacity, but a short little neck. The 308 is the same as the Savage in the short neck, short throat problem. Neither is great for shooting cast bullets, except under certain constraints. The 30-06 is a hair over ideal capacity, all things considered, but at least it has a long neck. Works well with both cast and jacketed bullets from 85 to 250 gr. The SAUM is great, if all you are shooting is jacketed bullets, as it works in a short action, maximizes efficiency with capacity greater than 30-06. All cases larger than the SAUM are also only of benefit if one does not want to shoot cast bullets.
If I had a favorite, it would be something like a long-necked 308, or a 30-30 or 30-40 AI, depending on whether I am shooting a bolt gun, lever gun, or single shot.
