RWS or Gamo, and in .22 cal.
.177 cal pellet rifles are more typical among the accuracy shooters, but they’re underpowered for taking down a squirrel or rabbit. I’ve shot many squirrels with a .22 cal pellet rifle.
Squirrels are nothing more or less than rats with a good PR machine behind them. If you look up the latin classification/taxonomy of rats and squirrels, you’ll see that my quip isn’t a joke.
In my small experience rats and squirrels generally take 2 rounds of .177, one to pin them and one to finish them. I actually love squirrels, but if I had to “thin the herd” (it happens-there is definitely such a thing as too many squirrels) one shot with a .22 is a lot quicker and cleaner.