When it comes to managing my growing portfolio of domain names, I recommend and personally use GoDaddy. They’ve come quite a long way since 1997.
Some will argue that they still have a ways to go in certain UI/UX areas. I’ve been with GoDaddy as long as I can remember.
One reason GoDaddy is my primary choice for web hosting is because of the discounts I receive owning the number of domains I do and being a Discount Domain Club member.