I've Googled for "most reliable domain registrar" and there are thousands of hits, many of them just affiliates trying to get you to use their registration link.

The folks at HN are probably more able to judge this so I'm asking here for recommendations. Low cost or ease of web interface isn't what's most important. Reliable (ie can get help if needed, and my domain won't get stolen or lost, or the company won't go out of business) are the most imporant.

Thanks