For domain name auctions, besides GoDaddy:
Flippa used to be popular for domain names, but they are moving away from domains, concentrating on businesses/websites
NameJet auctions only names they approve
There are a few others that will post only quality names, then if there is an offer, flip it to an auction
Many use eBay, but I've found these are low cost and you might make a few $, nothing great
And, as
@creataweb posted, right here on NP (with no commissions or fees!), where you really find out how much a domain name is worth based on the name alone - not an "end user" price
Really depends on how good your names are. If you think they are good but nobody else does, you won't make money anywhere.