Feinwerkbau 65. Sold under the Beeman name at one time, as well as under the Daisy brand, as well as others.
There is a Diana springer model out there too, that sold under a couple different names as well, the identifying characteristic, is the pair of studs that stick out of the side of the spring housing. The Diana models use the Giss contra piston system to counter the recoil.
The real question that needs asking, is what's the budget? How accurate do you think you need? Are you looking for a $100 toy, or an actual quality air gun?
Cheers
Trev