I get asked this *all* the time. It is not bad to shutdown your system. But it sure in inconvenient. Best bet? Let it go to sleep (which shuts down almost all the system), or use hibernate which will bring you right back to where you were before.

Is it Bad to Shutdown My Computer Regularly or Leave It On All the Time?
Dear Lifehacker, 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.