Corsair and Seasonic are two brands that have a reputation for high quality power supplies that consistently earn high marks in technical reviews. They are reliable, stable, and come with a 5 year warranty. Some of the newer models come with a 7 year warranty. Lately we've been seeing a few other brands offering some high quality units. One example would be the Antec Earthwatts and the Antec TruePower New series which are major improvements over Antec’s older psu’s like the Basiq models.
If you are only going to use one video card, then the Corsair CX400 would be an appropriate choice. The Antec Earthwatts 380 would be an appropriate alternative.