Netim.com : Most extensions are available here and prices are competitive.

Porkbun : For the extensions they support, their prices are one of the lowest.

Dynadot : A great registrar with good prices.

Marcaria : For certain international extensions that are not available elsewhere, for instance, .sm domains.

CloudyHost : Excellent prices for a few extensions including .com and .al domains!

AfriRegister : Good prices and support for African extensions like .ne, .et, .ke and a host of others.