More info is needed; are you looking for a .22 pistol or rifle?
Both Ruger and Browning are excellent names in .22 pistols. For Ruger, look for a used Mk II or a new Mk III. Many people prefer the Mk II as the Mk III's mag disconnect and loaded chamber indicator have introduced some reliability problems (notably they're more finicky about the ammo you feed them than earlier models, so you find a brand that feeds reliably and stick with it); the Mk II also has more accessories as it's the older version, and the Mk III changed the design enough to make most aftermarket Mk II mods incompatible, but the Mk III does have aftermarket accessories available and will get more.
The Browning Buck Mark is simple yet effective. It comes in many flavors that are all slightly different; most notably, newer models have the URX grip frame which has a different contour than the older frame, so URX grips won't fit the "classic" frame. Other than that, compatibility is really not an issue; barrels, rails, sights etc are all interchangeable. Between Ruger and Browning pistols, I prefer the Buck Mark; the stock Camper model feels better in my hand than the stock Mk III. It's also incredibly reliable (I've only ever had one jam after about 500 rounds, with several different types of ammo) and pretty accurate (the gun is definitely far more accurate than I am; it has an adjustable rear sight and once that's dialed in a good shooter with a steady hand can shoot a ragged hole at 25 yds). I do wish I'd known the difference between the older and newer frames; the URX grips are pure bliss straight from the factory and the only reason I'd sell this gun would be to trade up on that grip frame (which, since it has the serial number, is the "firearm").
Concerning rifles, I have far more experience with Ruger than with Browning. I know Ruger makes a VERY good bolt-action in the 77/22, but that gun sells for ~$650-$700; quite an expensive .22. The 10/22, it's semi-automatic little brother, is probably the most customizable .22 on the planet. It's not as accurate as some more expensive models, but at up to 100 yards it's an excellent plinker, and practically anyone who hunts owns a 10/22 for target practice, plinking and varminting.
Browning makes a series of .22 rifles including a tube-fed lever action, a bolt-action with a rather odd bolt mechanism, a semi-auto similar to their shotguns and a stocked version of their Buck Marks. I would have to think the Buck Mark rifles are at least as good as the pistols, but I cannot comment on any of the other designs other than I've seen the T-bolt mechanism and would not trust it with a more powerful round than the .22LR. All of Browning's rifles are more expensive then the 10/22, so I say go Ruger if you want a rifle.