My favorite airguns are the older Beeman Weihrauch R1 and R7, made in Germany of the highest quality materials and workmanship. They both have the exquisite clockwork Rekord adjustable trigger, and will shoot under 1 inch groups routinely at 30 yards with standard open sights, the R1 somewhat further. It has the custom installed higher powered Maccari spring.
In the R1's favor is its higher power, and the fact that there is an extensively illustrated and very thorough user manual written by an R1 specialist that used to, maybe still does, have a very respected airgun website (sorry, forgot his name). The manual discusses disassembly, tuning, repair, etc in great detail.
The R7 is a scaled down version of the R1, and as such is a delight to shoot because the R1 is pretty big and relatively heavy. It is easier to cock, carry, and tote.
Both guns are made to shoot tens of thousands of rounds and last indefinitely. They are heirloom guns.