For the money? Remington 11-87. I'm not a huge fan of their rifles (they're ok - just not my preference), but Remington shotguns for me have always been the pinnacle of reliability. Others, not so much. Heck my brother's boss who we duck hunt with bought a brand new Beretta auto last season. $1500 if I remember right. Out of the box it was snapping on rounds about every 5th or 6th shot. They made it right, but still, for that kind of money that's pretty pathetic. My brother bought a Stoeger. Turkish made clone of a Beretta that's actually owned by Beretta itself. Result? Snapping and FTE's out of the box. My brother sent that gun back 3 times - kept coming back with the same problem. Eventually he ripped the customer service rep a new one and they agreed to send him a different gun rather than working on the old one. This one has worked fine and he loves it, but it was a lot of hassle.
I bought a CZ-712 myself that I've not been fond of (sometimes it doesn't like to return to full battery after a cycle - resulting in a failure to fire). Tons of people had had similar issues with Charles Daly guns.
On the flip side, every person I know who has a Remington has it working fine. I don't have their autos, but my 870 is built like a tank and has never let me down.
I'll admit based on relatively positive reviews I've been tempted by a Mossberg Semi-auto, but I think I'm going to end up with the 11-87 next time Dick's puts them on sale.