Whats the best way to sell a domain name?

Hi, I have been asked to sell off a lot of my companies old domain names, apparently they may be worth something. Some of them are fairly good, but the way people price domain names is a little random and I'm not sure what the best way to sell them is.

I've seen lot of people start threads about their domain names and try to encourage people to bid on them, but this seems like a lot of work and that the chances of finding someone with a genuine interest is rare. I have been looking at services like Sedo and Afternic. Has anyone tried out these with any success?

Any advice gratefully received!