Web standards are important. The fact that you are currently browsing this website, the way it looks, exactly what it took to send it to your browser – is thanks to many different people’s work. The creators of the various technologies this site depends on might not ever meet, but thanks to standards set in place by entities like the IETF and W3C, everybody’s work comes together in a good way.
I personally use the latest versions of Chrome, Firefox, and Safari. If you use any of the above my site will generally look like its supposed to. If you have to use Internet Explorer, please, please use version 8 or higher. Every page should validate per W3C, and if you find one that doesn’t I’d like to know.