The absolute best, most accurate airgun I have owned is a Gamo Cadet-S (walnut stock, all machined steel parts, not the cheap plastic ones from the 90s). It was a couple years old when i got it "new" around 1988, and it still shoots like a dream.
What do you want to use it for? Target shooting? Usually a .177 would be better, as I believe they're used most often in competition. Dianas/RWS are decent, weirs are better. For the money, though, as an entry level gun, you can't go wrong with a slavia 630 or 631 lux. They're extremely well made czech air rifles and they'll last forever. I've got my dad's 619 from back in the 50s that still shoots
If you want to hunt small game, a .22 would be the way to go. They don't shoot as fast, but that's not what you're after. You're after energy. Bad side is that .22 pellets cost more. You can set yourself up decently with about 175 bucks with a crosman phantom from wally world for 109.99, and a centre point 4x32 scope from ct for 49.99. I did just this, and after a small mod (threading the bleeder hold in the piston and plugging with a machine screw) it shoots around the 700fps mark with 16 grain pellets, not too shabby for a cheap springer and it'll shoot 2" groups at 40 yards for em if i hold up my end. On the other end of the spectrum, my dad has a diana 350 magnum .22 that shoots abotu 850 and will put 5 shots in a 2 inch circle at 70 yards. The magnum springers do take a bit of practice to shoot, using the "artillery hold" where you hold it loosely and let it recoil as it wants. It also kicks like a .410
