Toribash
It might help if you told us what you do, for instance I need 3DS MAX, mudbox and Blender, but you probably don't. I'd look into getting a good media player set for general media consumption (Assuming your a consumer is a safe bet by my odds.)

Some media players I've used and liked:
VLC
MPlayer
Musikcube
Picassa

Also it was probably already mentioned but you'll want OpenOffice or LibreOffice (either will do just pick one they are basically the same.) and notepad++.

[EDIT]
Oh you might want to mention weather you'll consider software you need to pay for, since you didn't say 'freeware'. I.E. Mathematica FTW. But if your cheep you can just use wolframalpha.com

[EDIT]
Also I'd consider getting two browsers just in case one decides it doesn't want to work one day (it happens), chrome and opera are both awesome browsers, personally I'd use firefox and chrome in your position, as if your browser breaks it's normally a security issue, and chrome is more secure than firefox/opera, but opera is faster so *shrug*.
Last edited by Vox; May 7, 2011 at 07:55 AM.
The things I usually get with a new PC are:

1)An antivirus and firewall (AVG, Avast, Kaspersky etc.)
2)Antimalware (Malwarebytes is what I use)
3)K-Lite Codec pack (for watching movies and video files. Also comes with MPC)
4)Word processing software (Microsoft word or equivalent)
5)New browser (Chrome, Firefox, Opera etc. Anything but IE)
6)Direct X