I (sort of) attempt to subscribe to DAT's philosophy, inasmuch as I try to standardize my weapons collection around a small group of commonly available cartridges. My somewhat large collection of wheel guns are all .357 Mags, with the exception of one. That one revolver is a large-frame Smith chambered in .41 Remington Mag. With its 8 inch barrel and 230 grain hollow point in a +P load I use it as a "safety gun" when hunting in the woods. With its ballistic specs nearly identical to the .44 Mag, and a rail-mounted scope, it's pretty accurate out to 50 yards. I wouldn't think of using it as a primary hunting weapon, but for close-in awkward situations it'll do the job.
My autoloaders are all 9mm, and I generally just use NATO surplus ball, which is cheap, and readily available. The ammo for my "house gun" however is typically a mixture of ball and Federal "Hydra-Shock", mags loaded with two rounds of ball, followed with two rounds of H/S, and repeating until the mag is full. The self-defense philosophy being that an intruder has a chance to live (with medical attention) by retreating or surrendering after the first two, but most certainly won't survive the next two rounds.
Rifles are pretty much all .308, and 5.56mm with the exception of my long-range "reach out and touch something" rifle, which is a Weatherby Mark 5 (somewhat modified), chambered in 300 Weatherby Mag. The ammo isn't easy to find, and generally expensive, but as its primary use is 600 - 1000 meter target competition, I load my own custom ammo, and once the brass is purchased, it's cost is not dissimilar from loading a .308.