For the most part, you can pick whichever TLD you prefer, though a few have restrictions -- you can't buy a .edu domain unless you run an accredited post-secondary school. Many, but not all, country-specific domains (.us, .uk, .jp) are restricted to citizens of the country in question. Unrestricted country domains are often used for "domain hacks," where the extension becomes part of the title, such as YouTube's alternate address, "youtu.be."
1&1 makes buying your domain name simple. The more complicated part is on your end in figuring out what you want your domain to be named. Once you have figured out what you want your domain name to be, 1&1 helps you with the rest. When you purchase a domain with 1&1, the cost is inclusive all the registration fees and affiliated E-Mail accounts with 2 GB storage space. Choose a domain package you need, and the registration is free. It includes sub-domains, a control panel, E-Mail account and support. Furthermore you use the website builder provided to you by 1&1 to construct your own website around your new domain.
SnapNames is a web domain name marketplace - meaning that they only deal specifically with domains that are currently owned by somebody else. They offer daily and premium auctions, private brokerage of domains, and buy-it-now listings for buying and selling domain names, including over 30 million domain names that aren't all, as you'll find on some services, exorbitant. They have over three million customers, including a significant number of small businesses, which is worth it.
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.