I heard someone mention an AR7 earlier.. That has to be the crappiest gun I've ever shot/owned. It's jammed since the day I got it and continues to jam every time you shoot more than 1 clip.
I also have a Ruger 10/22 and it's probably the best gun I've ever shot. I've never had a problem with it jamming and theres lots of add-ons for it. I'd definetly look into a Ruger, You won't be sorry.