I feel loyal to many...
Namecheap was my first registrar and I still have dozens of names there. Especially with promotions, some prices good. I have interfaced a number of times with their help system and without exception it was efficient, prompt, accurate and helpful. Like that they are now an Afternic FT premium network registrar. I feel loyal to them.
Epik. How epic is it that you can interact with a CEO, mention something to them as a suggestion, and have it implemented the next day? Pretty epic! I also super love how elegant you can make your landers, even have links, and that they have super flexible payment options. They have, for domainers only, great pricing on many TLDs. I have over 25% of my domain names there. Their interface is not as simple as, say Dynadot, but offers lots of power user features. Nice to be able to see visits, whois queries, etc.
NameSilo for me their interface took some warming up to, but I love the transparency of their prices, and they seem competitive in almost all extensions. Push super easy, other domainers like it when a domain is there. Landers good. They have their own marketplace with good commissions. They are both Sedo, Afternic enabled. I like that you can set payment plans there.
Dynadot If I was recommending a registrar to someone with modest number of domain names and new it would be this one, just because their interface is so easy to navigate and clear. They have their own marketplace with decent landers, great pricing on many TLDs, nice array of available extensions, are both Sedo and Afternic premium.
DomainCostClub I think this is a gem that many don't know about. With membership you don't get just a discount, you get true wholesale pricing. On all TLDs they handle. I have the plan that limits to 49 there, and sometimes I get better prices elsewhere, despite wholesale, and they don't handle a couple of TLDs I like, but overall efficient, great value. No marketplace and no Sedo Afternic premium fast transfer though. Otherwise I probably would spring for the unlimited membership.
GoDaddy To much of the world, registrar means GoDaddy. I don't have that many names there, but no problems personally with any that I do. I wish I did not have to pay almost $100 to get competitive prices on many TLDs (and I did not pay, is why I do not have many there). Can see it is a good solution for those with big portfolios who want to consolidate and the discount membership makes sense.
Name.com I love their monthly specials, but otherwise pricing good but not quite at Epik or Dynadot or NameSilo in general. I have a couple dozen names there. Their user interface in my mind is very good.
Gandi I have a few dozen names there, on some TLDs their prices are good for registration particularly. They have first class features for forwarding, DNS etc, and to me their interface is good (at first had trouble figuring out their cart which is not intuitive to me). Not a Sedo or Afternic partner though, or I might use them more, and no marketplace.
Porkbun On many names, Porkbun have the lowest prices by a few cents. I have had more names in past, but down to just a couple there now. Which I feel a little disloyal, as they say, it is an oddly satisfying experience. I like the playful way they name things and interact. I am pretty sure will have more there in future.
I don't use Uniregistry, but feel I should, and will probably look into it.
Bob