I like long games that give me a compelling world to explore and interesting stuff to do in it. Red Dead Redemption. Skyrim. Fallout 3. Borderlands and Borderlands 2. There are other recent examples, but those are all classics from the last gen. Generally speaking, given a choice between a longer game that I like and a shorter game that I like, I'll pick the longer game precisely because it offers greater value to me. The problem, of course, is that I don't know whether I'm actually going to like a game before I play it. I can make guesses, sure, I can avoid genres that I dislike, etc., but there's no way for me to know whether I like a game before I play it.
For me, Diablo III has been a hell of a steal. I think I paid $25 for it as part of a Black Friday sale? Something like that. I got my money's worth out of Dragon Age: Inquisition. I even got my money's worth out of Destiny, despite how soured I am on how the devs have handled changes. Same goes for Far Cry 4. I can argue, based on the price I paid, that I got value from AC: Rogue and Unity (because I basically paid 1/2 original retail). I have certainly gotten my $2.60 out of Olliolli.
All things considered, I don't think that evaluating a game based on your enjoyment and a cost/hour of entertainment ratio is a bad thing. When you realize that you effectively paid, for example, $.30 per hour of enjoyment, you get both the fun of a great game and the satisfaction of a good bargain. At $10/hour of a POS point release with a Day One 6 gig patch? Even that is instructive.
A while back, someone described the dot-com stock market bubble investing madness as irrational exuberance. I think we often approach games the same way - we let our enthusiasm for a world or franchise or idea run away with our wallet, only to figure out - too late - that we aren't getting what we were promised. I've done that. I'm sure we all have. But doing a post-mortem on the experience and identifying an actual, measurable, quantifiable way to evaluate our experience is meaningful because it puts it in perspective and offers us the chance to make a less irrationally exuberant purchase next time.
Hence why the only pre-order I have placed right now is for Bloodborne. That irrational exuberance? Destiny fixed it for me.