Video Player = Xine for DVD's, mplayer for all the rest
MP3 Player = xmms
Java Editor = Eclipse
Games = Enemy Territory
Browser = Firefox
Mail Client = Thunderbird
IRC = Xchat
IM = Gaim
Image Editor = Gimp
HTML editor = Quanta Plus
Burning Software = k3b
P2P = Limewire and Xmule
Command line Text Editor = vim
Office = depends. Full package = Open Office. Abiword(word) and Gnumeric (sheet) does a neat job.
Well, I think that's what I use the most
. Depends of course, what you do and what you want to do