I've still got a Daisy "spring-air" action BB gun that I got when I was a kid, basically the same as the Red Ryder style one that was famous, but without the Red Ryder markings. Still works too. I've also got a Daisy one-pump pneumatic BB/pellet gun that I got when I was around 10-12 that works, but probably needs a new seal. I bought a cheap $50 Crossman pellet pump gun about 5 years ago for the specific purpose of shooting some rodents in my back yard, and its already got seals that are shot, and is total trash.
When my father in law passed away, my mother in law gave me all his "guns", only two of which turned out to be real firearms - a semi-auto shotgun and an old Marlin .22LR - there must have been a half dozen different model Crossman air rifles - the kind that need multiple pumps, and hold either 20 or so BB's or 1 pellet at a time. Those Crossman pellet guns even after oiling the seals all had the same issue as the one I got about 5 years ago, and the seals were just shot. I ended up tossing all but one or two that I could get to work. Those things were not designed to be user serviceable, and you can't buy the seals.
I've toyed with buying a Gamo air rifle, so that I can "plink" in the backyard, or one of those Ruger XDM clones, but those need CO2 cartridges I believe, and I'm not a big fan of CO2 powered BB/pellet guns.