A quality 1911 or an S&W .357 K/L/N frame.
After 25+ years or so of buying, trying, selling, buying and trying again, I could have saved a lot of time, effort and money if I'd fast-forwarded to these choices. And would have become a better shooter years ago, as well.
And the .22LR suggestion is a good one as well, although when I started 25 years ago, ammo prices were not the consideration they are today.