It is always a great idea to look for domain names with no dashes but whenever possible, attempt to pick names that are short. Although some big corporations are using very long domains that are difficult to enter in browsers, some of them containing more than fifty characters, but you are highly recommended to stick with shorter ones, in the long term you will notice their values even more and better.
If you seriously are considering running a very big business, like managing a huge company with an office, registering several domains, with the same root and using different extensions can be nice, like the way Yahoo is doing. For smaller projects, just using the .com version seems enough. Search very hard to grab that available .com domain which is very great for sunning a business online.