I've had a hell of a time finding a good singlet to race in. I'm a pretty small guy compared to your average joe like most of the skinny distance runners on this site, so I don't know why this process is so difficult.
The asics jersey I've had is really heavy and too short to be tucked in. This combination makes the singlet slosh about. I've run in a few Nike singlets and they tend to get real heavy when wet. I think the closest I've come to really liking singlet is some random adidas mesh piece of work.
Does anyone have some favorites?