Best in all my .177 HWs are the 7.9gr Crosman Premier Lites from the box. My HW50 will also shoot the JSB Express well, but it seems every few tins or so I get a bad one. So I stick to the Crosmans as they have been consistent without a bad lot for several years now. Another plus to the Crosmans is that they are harder than the JSBs, and won't get dinged up rattling around while hunting.
Don't give in to the funny shaped pellets, none of them make any difference with a well placed shot, and they also won't save a bad shot. A good old round domed pellet is all you need. I've killed a wheelbarrow load of squirrels with my HW50S running at 10fpe over the years. It's a great gun for hunting, super easy to shoot accurately and a joy to carry.