Is it bad to shutdown my computer at night?

Chances are good if you have been around computers for a while someone has asked you the question "is is better to shut down my computer at night or leave it running?". Lifehacker attempts to answer this question once and for all.

 I've heard it's bad to shut down your computer every night. Is it really better to leave it on all the time? I have a high-end machine and want to take care of it but I don't know the best way to do that.