I've always been a fan of
Airgun Designs.
Their old Mag was fucking awsome. You either loved it or hated it. Some people have a hard time playing with it. Chops a lot if play with it the wrong way. But ones you learn how to play with it, it's unbeatable.
This summer I've been playing with their E-Mag.... I LOVE IT! You can run it bot in electro and non-electro mode. Awsome if the electro breaks or you forgot to charge the batteries.
Now I see that their now X-Mag is out which will rock peoples socks off
http://www.airgun.com/Products/blue_xmag.shtml 