Computer Essential

[Bube]

Well, almost everything I use has already been said here.

Here are a few more I like:
GOM Player - Slower than VLC, but it has internal codecs so no need to install tons of them.
Digsby - Like Pidgin, but also has Facebook updates and Facebook chat integrated. I never thought I'd be using it as much as I do.
Frostwire - You know you want it. Free Limewire-like file-sharing.