If you want to build a website about cars, for example, a domain like www.drive.it is really nice and brandable (Drive it!), and would be just as good as any .com. If you want to build an MP3 site about rock music, rock.fm would work perfectly, there's no need to dish out shitloads of money for rock.com.
Also, if you are trying to penetrate a local market where majority of speakers are not English (like Spain, Poland, etc), doing it without a local domain is virtually impossible.