First and foremost, something that can take wind. Next consideration, space (for lo-o-ng periods when the winds force you to stay put). Lastly, weight and cost.

For a two-person model, an exceedingly safe choice is ’s Mountain 25 ($500). A classic design—geodesic geometry with four poles (two more for the vestibule), rugged materials, and roomy enough for you, a mate, and all your gear when you’re stuck in there for a week. Weight is not bad—around eight pounds, depending on the number of extra stakes and tie-out lines you take.
This tent has plenty of worthy rivals. ’s Trango 2 ($550) is the same basic design, with a little higher-end materials (Scandium poles vs. aluminum, for instance). Two person, vestibule at the head end, a bit larger than the Mountain 25. You’ll also do fine with ’ Stretch Tiros 2 ($479)—the same two-person, four-pole design as the others. It works. People don’t fool with it.
The wild card is a tent such as ’s Nammatj 2 ($575), a tunnel design that requires staking. But you save weight (it comes in at around six pounds) and of course ANY tent needs to be staked out in high winds. Otherwise these are fabulous tents—top-end materials, beautifully made, spacious, well-ventilated. I’d give it very serious consideration.