You must bear in mind that your domain has to be easy to remember and, of course, it must clearly identify your company, product or service.
.COM is the most popular and generic address ending on the Net what will place your domain at the highest level.
If the domain you wish to register is currently in use by others, you may choose a different name altogether or think of a slight variant of the original name. This is easily accomplished by shifting some of the elements that make up the name of your domain, for example using something as simple as a hyphen ("-") .
Remember that names for domains are unique and unrepeatable, so if you have already made up your mind on the name and it is available…