Go for www.domainname.com. It helps a lot when there's a single name comprising of continuous letters, instead of a name that uses hyphen (-). And again, even if you target a specific geographic location, www.domainname.com will help you in achieving good rankings in local SEO results. Good luck.
It doesn't help anymore then a hyphen version for local SEO. You would want to get a ccTLD if you want to target a specific market.
Domain strategy is an integral part of anyone's online marketing campaign. To have your domain name work for you and your business from a branding and search engine optimization point of view, which results in increased traffic and business visibility for your site. For more information on domain strategy and to see me putting these words into practice, feel free to visit my blog and follow me with my own domain developments.
Both can be used if we're talking S.E.O., but if you can choose, choose domainname.com ( usability reasons ).