It all depends on usage;
If you are one of those people who use it, and then don't know when you will need it again (today, tomorrow, etc.), turn it off!
If you use it repeatedly throughout the day, and have easy access to power, sleep it!
If you use it from time to time throughout the day and do not have easy access to power, hibernate it!
If you are taking it mobile and want to maintain battery power (like heading out to the airport for a long flight), hibernate it!
BTW, to people with hard drives (not SSD), I have to say that rebooting it often is NOT ideal for performance. I noticed that with so much staying in RAM during sleep, the performance was immediately GREAT when waking up. But if you shut it down, you are reloading what is common into RAM and you lose that benefit. With SSD I do not see that so much as disk access is so much faster.
R