On the cheap but reliable side, for a single AA light, something like the River Rock (from Target stores) is a good bet. I'm not sure they still carry this particular one, but their "River Rock" flashlight label has had great bargains on excellent lights.

http://www.candlepowerforums.com/vb/showthread.php?t=167899

The second generation Inova X1 would be a good light as well, but with two other generations of the same model, it can be hard to find the better second generation one.