I've got an RWS 350 Magnum in .22, that is very accurate. It's out to Vortek right now getting a Pro-Guide 2 installation and a custom muzzle brake. Apparently, my rifle is too old and internal dimensions have changed, so they have to custom build a Pro-Guide 2 for my rifle. But before it went out to them, I put it through the chrony using the stock spring and it was shooting 14.3 grain pellets at 850 fps - more than enough to airgun hunt in NYS. And supposedly, with the Pro-Guide 2, it'll be a bit faster. I asked him to get it up to 900+ fps if he could. My other .22 cal. pellet rifles are both CFXes that are in the middle of some upgrades. Stock, they are pretty accurate, but I've got upgraded triggers on them, one of which is the GTX trigger I found on Airguns Of Arizona's website (and I figured I'd give that a try), where I also found the NCT trigger for my NPSS (also in .22, but not shooting at speeds I would like), and another with the GRT-III trigger. I'm finding the GTX trigger much easier to tune and set at the 2nd stage with a better positive feel of the 2nd stage stopping point. I've also got a Theoben gas ram on its way to me from Airgunwerks.com for one of my .22 cal. CFXes which is said to increase velocity by 20 to 30 fps.
I recommend the RWS 350 Magnum for it's power and accuracy straight out of the box, but I also recommend the CFX for customization and the underlever feature most of all, because a fixed barrel will be inherently better than a break barrel that is prone to barrel droop.