For no particular reason that I can come up with, I was thinking over how I rate movies, and attempting to quantify the basic reasoning for each star of a five-star rating system. I think I’ve pretty much nailed it down.
* (one star): Two hours of my life that I won’t get back.
* * (two stars): Not a total waste of time, if the viewing cost is low enough (free coupon, someone else is renting it and I happen to be around to see it, a good Netflix plan with relatively high turnover).
* * * (three stars): Worth a rent.
* * * * (four stars): Worth seeing in the theater (at a matinee, or at an evening show if I’m either excited enough by the particular movie or feeling rich enough to afford it), possibly worth purchasing (preferably secondhand or after a while so the price has dropped, but perhaps at full price if I think it’s on the high side of four stars).
* * * * * (five stars): A keeper. Worth seeing in the theater if possible, worth owning at whatever price I think is reasonable.
Of course, as with any rating system, there’s some amount of variability, and my movie collection certainly isn’t entirely comprised of 4- and 5-star movies (Star Trek V? Honestly, it’s about a 2-star movie. But it’s Star Trek, and I’m a nerd and a completist). But on the whole, I think that’s a pretty good overview of my thought process.