SNPedia.com
If you've had some of your genome sequenced, SNPedia can tell you, along with Promethease, what that might mean for you. I think the main value right now are the drug metabolism results.
Turns out I have a relatively nonfunctional enzyme, and it effects my metabolism of a whole class of drugs. The prevalence for this kind of issue is fairly high.
The caveat that the SNP-drug interaction literature is preliminary seems important to add; many such results fail to be replicated.
It suddenly occurred to me that not everyone uses a website I love. Of all the websites I browse if you asked me which one improves my standard of living in the largest, most concrete way, it would be slickdeals.
What it is: a community driven "hot deals" website with voting. By itself this is already useful, but the best feature is deal alerts. you never have to actually browse slickdeals. Just create an account, set up deal alerts for whatever strings interest you (I for example have a deal alert for "whey" to get alerted to deals on whey protein powder).
More than 50% of my belongings come from sales I've been alerted to via slickdeals. Any big ticket items I need, but don't need immediately I just set alerts and wait. My laptop, desktop, tablet, smartphone, clothes, toiletries, books, games, even some food are all slightly better for the price I paid than they otherwise would have been.
So what other sites am I missing out on that would make my life a lot better?
A website I just discovered for habit building chains.cc seems cool, but I haven't had time to evaluate its usefulness yet.