Professional Expired Domain Hunting
Godaddy is possibly the biggest domain registrar in the world. The general, non-coupon, prices are decent but after adding whois protection do not really compare to NameSilo or Name Cheap.
.COM for $0.99 Coupon: CJCRMN99U
GoDaddy changes coupon codes regularly and will occassionally have unbeatable deals with their coupons so check back regularly for domain deals.
Free Whois Privacy - Best Prices
I use NameSilo all of the time, even for this very domain, as they generally have the best prices overall and with the coupon code below you can get a further $1 off any domain.
$1 off any domain Coupon: DomainHunterGatherer$1
For everyday pricing that cannot really be beaten, especially with the free whois privacy, I would recommend NameSilo all day long.
Free Whois Privacy
NameCheap is a great value domain registrar with free whois privacy and no upsells so you get no surprise costs when registering domains.
NameCheap also have some good deals on SSL certificates.