I have no personal experience with REI tents, but from what I've seen in the stores and heard from friends who own them, they are great values, and function very well. The two-person versions are definitely worth a look, and the cost savings might allow you to get a solo tent and a two-person tent. (You could carry both tents on easy trips, storing gear and sharing cards and conversation in the larger tent, and each person having his own tent for sleeping.)

Kelty and Sierra Designs tents are also worth a look. However, in all three brands, you're probably going to find the 3-person versions too heavy for solo use. If you do end up with a 3-person tent, you can get two smaller stuff sacks and split the tent: one person carries fly and poles, the other carries the inner tent.

Like most other gear, you can choose only two of three features: light weight, low price, and good quality.