Brandroot - Great Names for Great Ideas
Instant Username Search - Check out if your username is available
Zlipa - Startup names with available dotcoms and logos
Namechk - See if your username is available on 100+ social networks
BrandBucket - The original marketplace for business names and creative domain names.
Namesnack - Really good business name generator and instant domain checker. Powered by A.I and 100% free.