I made the decision yesterday to start listing out my backlog, separating it by games I owned and those I don't. Granted, the list includes some classics from HD collections and some PSN games that won't require quite the same amount of time as others, but these are balanced out by lengthy games I have yet to finish such as Fallout 3 or Persona 4 Golden. In a moment of both disgust and excitement, I counted my backlog at around 50 games. FIFTY. My backlog is made up of PS3 and Vita games--I've given up on anything from previous generations until I'm retired. 
For insight into how it could have gotten so large, a few factors play into it.
I got PS3 at launch, so I've had one since November 2006. My original 60 GB Fat died with the YLOD and after bringing it back to life with a heat gun to transfer my data to a new slim, I was rocking again. I currently have two slims, getting the second when we were in the market for a Blu-ray player for the living room. I got my Vita at the end of 2012.
I'm now 30 years old and will be turning 31 next month. Though a year and a half removed from college when I got my first PS3, I have since moved twice, changed jobs once, bought a house, got married, and completed several home renovations including installing hardwood floors and remodeling our kitchen. I have no kids, though a fairly demanding job as an IT manager for a small company. We don't have any kids yet, though.
I think outside of having "real world" obstacles to my free time, the other big catalysts to my backlog were: trying to play every game, my completionist tendencies, and playing games that were either bad or I didn't enjoy.
Though I didn't really try to play every game that came out, I sure did try to play as many as I could. There were obviously a lot of games I didn't offer at because they didn't appeal to me. For example, I don't play the yearly military shooters (COD, Battlefield, Medal of Honor) or Madden as they're boring and repetitive for me. That doesn't mean I don't love FPS games sometimes (Borderlands for example) or football (Go Browns!), just using this as a point that though I tried to play a lot of games, it doesn't mean I wasn't somewhat selective in my gaming choices. All that being said, I tried to play every good game that came out that appealed to me. I couldn't sacrifice any. If I didn't have time for them but they were on sale, I'd buy them, thinking "I'll get to them later", amassing a nice collection along the way.
This could have worked if not for a big mistake on my part in the middle of this generation, and one bad (and good) gaming habit. First, the habit. I'm a completionist. I love exploring every bit of a game, and I love a challenge. Then, well...Sony introduced trophies. All the sudden I had a quantifiable measurement to apply to my bad habits. This wasn't vastly altering my gameplay, but it did make me do something a gamer like me doesn't have time for: play bad games. With the amount of free time I have, I'm forced to prioritize my gaming experiences, and a mild trophy obsession midway through this generation caused me to go astray and my backlog grew by leaps and bounds. Let's put it this way: I platinumed Sonic Unleashed.
I've learned my lesson though, and with PS4 preordered I'm working my way through, only focusing on good games I'm dying to play, prioritizing them as they align with my interest. I'm also no longer trophy "obsessed", though I still enjoy collecting them and will always be a bit of a completionist. I've since sold games I haven't enjoyed or that are "bad" back to GameStop, and crossed games on my play list for trophy only purposes off for good.
What I definitely learned though is the only time to ever play a game that falls into the "questionable" pile is when you have nothing else to play. The only exception is when it's only "questionable" because it's outside of your gaming comfort zone, as new experiences should be sought out regularly.
What's your backlog like and how did it get to this point?
