I would pick whatever gun was most appropriate for ridding the earth of the f$#@@ck nut who decided to pass the law limiting us to only one gun!!!
Ha, but seriously, I'm not really sure. I love my SKS, but it's not top of my list if money is no object. Neither would an AK, butif money is a factor a high quality AK would probably be my choice.
I really like my friend's AR15, but the cleaning issues make me hesitant. I've seen his fail to feed right when clean but lacking a little oil. .223 isnt a bad round all in all, but I like how my 7.62x39 will go right through a tree.
I also own a winchester 94 (30-30) and a remington 870. Both good choices in the bush rifle or shotgun catagory. The 94 is just so sexy and smooth. Still, if I catch a soon to be deceased burglar in my house, something semi-auto would be nice. 870s are awesome shotguns, but there's still something about the bayonet lug and slamfire capability of the winchester 97 (or norinco remake) that has a lot of apeal. What's scarryier than a shotgun being cocked in your face? A shotgun with a bayonet pointed at you!!!
Not sure if I really have the experience to call this one well, but I guess I'd have to say something around a .308 caliber with some kind of shotgun mounted underneath. Fantasy? mostly, but Im sure someone's tried it before.
Though a M16 w/ m203 would pack a nice little punch.....