I actually read your question and will answer it literally: a K-38/ M-14. That is what it was made for, a target revolver.
If, as others seemed to read into the question, which single S&W revolver for all needs, a Model 66-3 with four-inch bbl. and Pachmayr Presentation grips. I'd fire mainly .38 Special ammo most of the time, but .357 power is an option when really needed.
If a second S&W, a Model 60-7 snub .38 or a M-60-4 with three inch barrel and adj. sights with a full lug barrel. I love both the M-60's so much that I'd hate to be without either, but the M-60-4 is harder to find, so I guess I'd choose it. But I'd skip movies and most meals out until I'd saved enough for a snub one, too. But these are not for target shooting. That is not their proper role. They ARE ideal in other roles.
Why do you want just a target revolver? If you're serious about match use, you need a .38 Special auto or 9mm if rules for your matches allow it. A target-tuned .45 auto is the other gun you'd need to compete seriously in traditional bullseye matches. You did say to "shoot for fun." That implies that you don't intend to be a serious target shooter, in hard competition. So, any of those mentioned above will suffice. But the M-14 is what was designed for target shooting, or the M-1955 .45 Target model. The .45 is big and heavy, so I'd choose the .38 Masterpiece. The .38 ammo is cheaper, too.
I hope you have other handguns for other needs.