I've only recently started using Namesilo, but in polls on here they are highly rated, including privacy free is a big plus, and their interface for both managing and finding domains are user friendly in my opinion. I REALLY like that Namesilo, more than other registrars, have consistently low prices, with consistently low renewal rates.
GoDaddy prices are less competitive (although they seem to give out 20% or 30% off to customers often which make them more competitive). One big advantage is though that they are so big and advertise so much everyone knows them, so a push to new owner there is more highly accepted.
Both GoDaddy and NameSilo qualify for fast transfer and getting on the Afternic premium network, if that is important to you.
I have used GoDaddy, NameSilo (only recently), Namecheap (a lot), Alpnames and Web Hosting Canada. To be honest, once used to them, I find all of them good. I use the TLD List to find the best deal on the extension I want.