Common screen resolution?

I'm developing a web application which is quite information heavy. This means that every pixel available in the screen for display helps a lot, to avoid the UI looking too cluttered and to display relevant data.

I was wondering: which is the "common" screen resolution? Years ago it was something like 1024×768, but nowadays it must be something much higher. I can't rely on what I use as I'm a developer and I probably have bigger screens and resolution than the average Joe user.

So, where can I find the currently recommended resolution for webapps?