Here is a slightly different question.

My Internet is covered with Firefox (Which i use in windows also).
My email client is Thunderbird.
Crossover drives my office2000 copy (I'll consider OOO once it gets better.
Its a very good suite right now that deserves lauding, but its still behind Office).
When I want to game I got Cedega CVS curteosy of Linux Gamers.
When I need numerical cruching, mathworks provides a Linux version of MATLAB (thank god for cheap software being a college student!)
BMP provides my MP3 playing capabilities and other things
K3b provides my burning (I know, I know!!! Its KDE, but I can't find a nicer program Although I heard there is a Nero Linux and since i'm used to Nero on windows I may take a peek
SCIM provides me with foreign language input for my language classes

But you know what keeps my windows activity on?

INSANT MESSAGE. I can never send a file right...maybe 10% of the time it works~ the other 90% it never does! Also, MSN support is REALLLY weak. I can kind of understand the fact I don't get winks or I can't "nudge" someone...but I can't even use "non standard" emoticons!
If sending a file via AIM or MSN could be fixed...and get MSN support up to par, then I would wonder why Windows is on my HardDrive. But until then I find myself booting up over and over in windows because I want to send a file to a friend, or because a friend is using many different emoticons that Iwant to see.
Linux isn't absolutely perfect...I know that. But its dissapointing to see how long the New MSN has been out with no real progress in that (and just file sending in general!)