I've regularly used namewinner and pool over the last year, and each has caught its share. Head to head, pool probably beats NW about 2 to 1. Club drop has improved it's success greatly in the last seveal months as well. I have been trying snapnames lately since they changed, and they do seem to be well in the running with some advantage on .net/com due to the new arrangement to be guaranteed drops from NSI. I tried godaddy a couple times, but have never liked the old snapname model of buying credits. You can sign up monthly, but then pay a fee whether you get a name or not. Most of the others are not successful enough to use seriously except as a backup when trying really hard for a name.
As to pricing, godaddy is about the only one left at fixed pricing except dropwizard.com which is at $120 each, so the end pricing is unknown until you know the competition. Pool is horrible now where you actually have to win two auctions to get a name if anyone else is bidding.