Creating a new site soon and was wondering about SEO and the domain name I choose. In the past I just made the domain name relevant to my site but this time I want to put a little more thought into it, SEO wise. I have narrowed myself down to 3 domains and was wondering which will help my site rank higher easier. All three have similar keywords but are a little different.,, Normally I like to keep my domains as short as possible, but even though these domains are multiple words, I think its ok . Which has the best keywords to help get my site the highest possible in google's rankings and why?? Any help or insight on this would be greatly appreciated, thanks :)

(Also this post may have been better off posted in the keywords section, new to this site and did not see that at first so sorry about that.)