I own pistols in, and handload for SA pistols in 38spl, .357mag and 45 Colt as well as for semi-auto pistols in 40s&w, 10mm, 45acp, and 45 Super. (Note I don't shoot a 9mm.) I think the best caliber hands for SD including defense against 4 legged creatures is hands down the 10mm, especially if shot from a 6" barreled semi-auto like the Glock G40.
My custom 6" slide Glock G20/21L I developed way back in 2004, long before Glock or anyone else thought of a 6" 10mm, can shoot both 10mm and 45 with just the swap of a barrel and mags and the 6" barrel in both calibers really helps performance. Especially the 10mm where it produces velocities using Power Pistol powder that are hundreds of fps faster than in a 4.6" barrel.
Ballistically, the 45acp or 45acp+P in any bullet weight from 185 to 230grn can't hold a candle to the performance of 10mm in any bullet weight from 155 to 200grn. It's not even close. As the bullet weight drives the price of reloading, the reloading costs are very similar excluding brass, for a given bullet weight. Amortizing the cost of 10mm brass over 6 loadings means that the costs of loading the 10mm is comparable with a 45acp or 45acp+P as most of the bullets I shoot in my 10mm are 165grn vs 200grns for 45.
Comparison of chrono'd performance of my 10mm handloads with my 45acp, 45acp+P, and 45 Super handloads performance in my G-20/21L:
6" G20L 10mm using Power Pistol powder:
165grn handloads @ 1,503fps = 827ft/lbs ME
180grn handloads @ 1,479fps = 874ft/lbs ME
200grn handloads @ 1,383fps = 849ft/lbs ME
I also have a 165grn 'nuclear' load I developed that does 1,589fps and 925ft/lbs ME - YES, 1,589fps!!
6" G21L 45acp:
200grn handloads @ 916fps = 381ft/lbs ME
230grn Winchester @ 897fps = 411ft/lbs ME
6" G21L 45acp+P:
200grn handloads @ 1,103fps = 540ft/lbs ME
230grn handloads @ 1,009fps = 520ft/lbs ME
You have to go up to a 45 Super to equal the performance of the 10mm
6" G21L 45 Super using Power Pistol powder:
200grn handloads @ 1,291fps = 880ft/lbs ME
200grn handloads @ 1,307fps = 891ft/lbs ME
The recoil of the 10mm, even my 'nuclear' load, is surprisingly not harsh as one would think. It's a definite strong push rather than a snap. In part that is because of the longer 6" slide and barrel of my custom Glock or the G40 Glock produced over 10 years after I developed mine. There also isn't the barrel rise of a magnum caliber in a revolver as the bore axis of the Glock is significantly lower than any revolver so followup shots are much quicker.
However, the same can't be said for my 45 Super loads in the same platform (only different barrel and mags). For some reason, it produces a much stronger recoil. Still no snap, however, the push feels much stronger and I honestly don't know why, it just does. Not just to me but to everyone I let shoot it.