The top 5 domains are:
.com: Hands down the most popular TLD available. It’s also everyone’s first choice. Most of the time, if someone doesn’t choose a .com domain, it’s because it’s already taken.
.net: .net was originally reserved for ISPs and networks, but has now become a generic, openly accessible domain. The general opinion regarding .net domains is that they are associated with web applications and services.
.org: .org was originally reserved for non-profit organizations, but is now available to everyone. People typically perceive .org websites as trustworthy and legitimate.
.co: .co was originally reserved for the country of Colombia, but is now available to the general public. If you are building a website for your business, then a .co domain is a viable choice.
.us: Unlike the top 4, .us domains are reserved for people and companies in the United States. It was originally used only by the US government.