Namecheap — This company provides .com domains for $10.69 (plus 18 cents) per year ($9.69 if you transfer from other registrars). Along with your domain, you get free email forwarding, free web redirection (where anyone going to your domain is automatically directed to another address of your choice), free domain name parking, etc. For the first year (or at least, at the time I checked their prices), you can also have their WhoisGuard (where your particulars are masked from public view) for free. They have a wide variety of domain name extensions available, including .net, .org, .biz, .info, .us, .co.uk, .co, .de, etc. You can use either a credit card or PayPal for your purchases.
HostGator is a company I used for many years with an old firm, and I've found them to be fairly reliable as a rock-solid grounding for a bandwidth-heavy site. Their control panel is also fairly powerful, allowing you to automatically control your fleet of names, as well as locking them down so that nobody can snipe them if you accidentally let a renewal lapse. Their prices are competitive but not the best, but I've found them to be immensely reliable in the past. Read our HostGator Review.
A great domain name is a concise, easy to type, and memorable URL that reflects your brand or your website’s subject matter. Avoid using hyphens, strings of numbers, or unnecessary words to make it easy for your visitors to remember and find your website. Remember: A great domain name is one that your visitors can type correctly on their first try.