Hello as you stated there are many choices. What size critters are you looking to dispatch? Here are a few options and its pros and cons.
spring guns (self contained no need for an extra air source)
HW 30 Pros : light, easy to shoot and cock, can take game up to squirrel size. Con: limited to squirrel size game
Diana 54 Pros: accurate , easy to shoot, more power than HW30 so can take larger game/critters raccoon/woodchuck Cons: heavy
pcp guns (needs an extra air source pump, cylinder, or compressor)
Benjamin marauder pistol/carbine Pros: quiet, accurate, light, 32 shots per fill, squirrel size game Cons: limited to squirrel size game
Benjamin marauder rifle Pros: quiet, accurate, more power than pistol version and 25 cal available as well, larger game/critters raccoon/woodchuck Con: heavy
All the high end end pcps will do what the Benjamin Marauders will do with a lot higher price tag, maybe a better shot count depending on the gun and a little better accuracy but I just listed a few quality starter guns what should worry free and easy to accessorize. Hope this helps if you have a specific question about a specific gun just ask there are many people here who have or have had that gun and can give you first hand experience. Good luck in what you choose and I hope this was some help Eric