There is no "best registrar" , all registrars are good to some fields but not for all ( Certainly not godaddy.com - some of the reasons why www.nodaddy.com )
Namecheap is the best ! especially you can renew/reclaim domain even after expiry date IInd for me is Godaddy: BTW they do accept paypal
Godaddy officialy suck they added the VAT to there site, best site is Moniker.com you can search around and you'll know just contact them about a special discount and you will get domains at 7 $/year
If I had to choose I would go with Namecheap.com. I've used them before and never had a single problem. On the other hand I have had many issues with GoDaddy.com over the years and even though customer service eventually handled the problems it wasn't worth the hassle.
Onlinenic is a good one. A had some issues trying to transfer domain names to namecheap. The online process didn't work and it was like pulling teeth to get customer service to respond. Godaddy are golddiggers. I had a domain expire and within the 30 day grace period they tried to charge me $65 feee to renew.
I use NameCheap.com, and it is serving me very well. I have tried name.com (they are good but it takes ages to load the accounts page, and ages to transfer a domain to some other account), GoDaddy.com (only good for "buying" .info domains-you renew a domain late, they keep the domain with them because the price they ask is 6-7 times the original renewal time, so, I do not deal with them for other than .infos), Register.com-these guys are OKay, guess I haven't given them enough time to please me because I use NameCheap.