I've always gone for leaving my machines on. I feel there is less wear and tear on components by leaving the machine on. Specifically, as I understand it, thermal shock to minuscule electronic components during power-on. In the past, I've lost a number of motherboards and processors due (presumably) to this effect. Since keeping my machines on 24/7 (for several years now), I have not had any such problems.
I have been turning mine off at night for years and never had a problem. Years ago it would cause a problem with the hard drives but that has been corrected. I do not even bother powering then down all of the time and I have never not been able to boot Linux. It does save electricity and if you are concerned about system maintenannce then all you need to do is ensure that anacron is installed and running. anacron will run the maintenance task which have been missed after bootup. Unless you have a very old machine you will probably not even notice.
"Everything should be made as simple as possible, but not simpler." Albert Einstein