During the 32nd International Public ICANN Meeting in Paris in 2008, ICANN started a new process of TLD naming policy to take a "significant step forward on the introduction of new generic top-level domains." This program envisions the availability of many new or already proposed domains, as well as a new application and implementation process. Observers believed that the new rules could result in hundreds of new top-level domains to be registered. In 2012, the program commenced, and received 1930 applications. By 2016, the milestone of 1000 live gTLD was reached.
Not every registrar sells every top-level domain, so if you want an uncommon TLD like .pizza, you might have to try a few registrars. Unusual TLDs often cost more than a standard .com address, but provide built-in memorability and give you more name options, since far fewer .pizza addresses are already taken. You can check name availability at any registrar that offers the TLD you want.
The right to use a domain name is delegated by domain name registrars, which are accredited by the Internet Corporation for Assigned Names and Numbers (ICANN), the organization charged with overseeing the name and number systems of the Internet. In addition to ICANN, each top-level domain (TLD) is maintained and serviced technically by an administrative organization operating a registry. A registry is responsible for maintaining the database of names registered within the TLD it administers. The registry receives registration information from each domain name registrar authorized to assign names in the corresponding TLD and publishes the information using a special service, the WHOIS protocol.
Hostt is a just-launched free web hosting company that includes domain name purchasing and registration. They've a suite of offerings, such as one where you'll pay $13.99 per year for domain names with extensions that include .com, .net, .org, .us, .biz, and .info., but have unlimited bandwidth, web space, sub-domains, parked domains, sub-domains and email accounts, among other things. Like HostGator, they include domain locking and automatic renewal, along with a user-friendly management portal (which, believe me, is pretty rare) and 24/7 technical support. This isn't a bad price considering the amount you get, and their $3.95 and $5.95 a month packages both offer fairly balanced domain-inclusive packages.
Hostwinds remains a user-friendly option for registration and hosting, even if you're transferring from another service. It lists out all the extensions to create your domain name with prices to register, transfer, or renew for each extension, unlike some services that bury these within the website. You simply enter the domain name you want and check the availability, and can theoretically get going in a few clicks (if it's available or taken). It will then tell you if it is available or taken. They've also got live chat, email, and phone technical support before purchase too, which is rather rare.
FatCow has one of the cheapest offers for an entire website package, with hosting and domain names for just thirty cents during your first month. After, that the price is $10.99 a month or $59.88 for the whole year, in a shared hosting package with enough bandwidth for most people. This is a limited promotion I found, but they still sell fairly well-priced packages (their "fat" options come with extras like marketing and advertising credits), and will gladly offer you perks for transferring your domains and hosting to them.