Hmm well you're a programmer so why don't you make something related to that? There are already lots of websites about programming of course, but to be honest few of them are good (talkphp is an exception I think, or do you know any others?).

It will be easier to stay motivated and don't forget that you need more than coding to make a successful site, "Content is King", so you'll need some of that as well, but if you're good at programming that's not a problem right?

Something I've been thinking of myself is creating a sort of web design/development resource site with news and tutorials, that might be interesting??