If you have an REI store nearby, I recommend you go there and let their treehugger staff advise you. REI is careful to only sell quality products, and consequently their stuff tends to be on the expensive side. You'll regret paying two or three times what you might pay for a similar tent elsewhere, but you won't regret it later when you and your better half find yourselves in a day-long rainstorm. (If you want to find out how compatible you are with someone, just take them camping in the rain.)
I have an REI Hobitat 4 tent that I've taken to Oshkosh several years. It's quite dry and is tall enough to stand in. Big enough for two cots with space left over. I also purchased the "footprint" that REI offers for this tent. It's a heavy ground cloth sized custom for the tent, intended to protect the tent floor. The campground at Oshkosh is a mowed hayfield, and I've had tent floors punctured by alfalfa stalks; the footprint takes care of that problem.