People are obviously going to put different weights on the different criteria. But I'll do my best here to go through what, from my observation, works. I'm going to use a 10-point rating system. Nothing under 6 points counts.
- What you consider adequate stopping power
.45acp (9), .40sw(8), and 9mm(8) are all adequate - ditto for .44 mag(10), .357 mag(9), and .38 spec (7)
-inexpensive and available ammo, for target practice and self defense
.38 spec(10), .357mag(9), 9mm(9), .45acp(7)
-inexpensive and available magazines / speed loaders
additional criteria: under $30
.38/.357(10)
1911s(10)
glocks(10)
sig(9)
beretta(9)
Taurus(8)
cz75(8)
Taurus(9)
glock(8)
(not really aware of warranty because I've not got the exp with needing one)
-easily available spare parts
1911(10)
glock(8)
taurus(8 or 0 depending on how you look at it)
beretta(9)
this category is subject to individual exceptions, but my observations follow:
.38/.357/revolver(10)
1911(9 depending on brand)
taurus(9) (personally flawless, but I've eard of others having problems)
beretta(9)
... and, I went on down the list and did the rest in my head, because it was taking too damn long.
What it comes down to in my mind, is either a low-end, inexpensive revolver (probably from Taurus), a low-end 1911 like a Springfield or RIA, a Ruger (I didn't mention 'em in the list because I wasn't personally sure - and I hate their ergonomics),or a Taurus PT111/140/145 or 24/7 (both getting big points for ergonomics, weight, price, and durability/reliability in my experience). To the exception of the 1911s or a new S&W revolver (used .38s can be had for under $400 and used .38 or .357 taurus revolvers for $250 or less), they're all in the same price range ($300-400). When a person considers that, short of the 'excessive' shooter and the rare scenario where a part breaks, they'll never need replacement parts or warranty...
So, in short, it seems to me that the best recommendation you could give someone who "just wants a gun for self protection and occasional shooting/practice" the best suggestion would be a used S&W revolver, a used Taurus, a Ruger, or a new Taurus. Given the fact that revolvers typically work for everyone's hands (at least one of the frames will, at least) and the same can not be said for pistols, then the obvious choice is a revolver. Doubly so due to their ease of use.
And this isn't even considering milsurps or older guns, like the S&W mod10, Star BMs, Makarovs, CZ82s (or 83s for that matter!), a PA63, and a number of others... once you get down below the $200 mark with older yet reliable and well-made firearms, you really can't say "you can only have one" because the value to price is just so damn high!