HTML, CSS, Javascript, XML, PHP and MySQL are cool to study.
Having HTML as the main markup language.
CSS to style mine pages.
Javascript to give mine website a little extra of effect.
XML to gather up data and let it easier to refresh on the page it self.
PHP for the prepossessing of pages that you can make.
MySQL for the User database information.

However, all of those languages have it's limit.
For example on Javascript you can Perform a function only once or let it loop trough an array.

So for some extra effect, maybe something for game based language I'm looking up for a new language which is even more dynamic.

I have been looking into Java but I'm not sure if I should study that language as it's being used less in the days.

Some recommendations would be lovely.