My backlog is terribly big. So big that I banned myself from buying anymore games atm. I only have a WiiU, a ps3 and a 3ds but there's more than enough for me on those, especially because I don't have a lot of time and have to work for uni a lot.
hmmmm lets see (I'm not counting all my virtual console games, because thats just madness, but I'll put in the noteworthy ones):

Ace Attorney Dual Destinies + DlC case - completed the main game, about 30% through the DLC, I think.
The Legend of Zelda Wind Waker HD - Not sure how far I am exactly but im going to go on a limb and say ca 25% complete.
Ace Attorney trilogy (replay) - 0%
Pokemon games...just pokemon games....
The Legend of Zelda skyward Sword - 0%
The Legend of Zelda the minish cap - 0%
The Legend of Zelda Ocarina of Time 3D - about 40% complete (geez notice a pattern here?)
Pikmin 2 - about 60% complete
Pikmin 3 - 0%
Super Metroid - about 70% complete
Metroid prime trilogy - 0%
Donkey Kong Country Tropical Freeze - about 25% complete
Ni no kuni - about 85% complete
Life is strange - about 20% complete

It goes on and on that was just the list of the top of my head. I think I might have a problem.

Those were the days!  I wouldn't even buy another game until I finished the one I already owned (as long as it actually had an end! Some games were endless).  It was when I walked into Gamestop and walked out with TEN games for my PS1 that I realized there was a problem.  

Not great. Been spinning my tires in GTA5 for a while now (figuratively and literally), about 70% complete (not counting the online side of things).

Not too terrible. Working on Witcher 3 and left behind RE1 remake.

I live in fear of the 4th quarter on my Xbox. My PS4...not so much. LOL

My Xbox Backlog goes like this (All of these games were either Xbox Live free games or digitally purchased during sales)

Child of Light
Halo Spartan Assault
Halo ODST
Rayman Legends
Strider
Tomb Raider: Definitive Edition (Im ready for a refresher to get ready for the new Tomb Raider)
Wolfenstein
Wolfenstein: The Old Blood
Sunset Overdrive (All of the DLC)
The Evil Within
Shadow of Mordor (plus DLC)

Painfully awaiting:

Gears of War: Ultimate (Deluxe edition)...including the free Gears collection that comes free when you buy ultimate before a certain time.
Halo 5
Tomb Raider 2

Fallout 4

Forza 5
(Backwards compatibility in November which includes...Mass Effect)
Witcher DLC

PS4. Nothing really...just waiting for Until Dawn and 2016. To tell you the truth, I should really hold off on Until Dawn. Its really not a prioirty with all thats going on this year.

Still huge (like, multiple hundreds), but with the number of games that I have, it's always gonna be huge. I do feel like I beat a good number of games this summer. At least, a good number considering I had to work 9.5 hours, 5 days a week all summer.

I always have a pretty big backlog but looking at some of what the others here wrote I guess it isn't that bad. I am not sure how many titles on my PS3 I still have but it is quite a few. Do not have my Xbox 360 anymore so those are no longer an issue. Finally just finished Red Dead Redemption after 5 years for the PS3 and Evil Within for the PS4. Started iFamous: Second Son again but just cannot seem to get into it. Think I will finally work on Shadow Of Mordor until Mad Max (depending on how it turns out, still a little on the fence about it), Until Dawn, and then MGSV. I will probably jump on one of those when they release. Once November comes I will be in the world of Fallout 4 for who knows how long so I definitely would like to work through some of the backlog before then. :)

My completion rate has dropped dramatically due to a house move...
Wii U backlog
Deus Ex
AC4 Blackflag
Legend of Kay
Metroid Prime Trilogy
Bayonetta 1

Child of Light

PS4 Backlog
Theif
Murdered soul suspect
Sniper Elite 3
The last of us remastered


3DS backlog
Zelda a link between worlds
Paper Mario sticker star

In 3-4 days I will get platinum in Bloodborne.
Then I will start Call of Duty: Advanced Warfare and The Witcher 3 where I want to get the platinums too. I should be finished with them at the end of the year when Call of Duty: Black Ops 3 releases which I will buy and play online with friends. And then early 2016 Uncharted 4, Dark Souls 3 and Ratchet & Clank will release which will be a great gaming time! I am also planning to buy Just Cause 3 end of 2016 and hope that Tekken 7 will release on PS4 at the end of 2016.

Not good at all. I have so much stuff.

Today, I was rolling around on the bed whining about Fallout 4 and Persona 5 not being out, and I was like, "aahh, I just want to play something," then I rolled over to the point that I was looking at my games shelf and I instantly felt guilty about all the unplayed games there, so I turned away like I didn't see anything. I hid my shame by napping.

Sometimes I just don't want to start new games that aren't the games I really want to play. It feels like so much effort.

I did just finish Dishonored, though, finally, and I did try Dead Island again, but I quit because I couldn't fine tune the mouse control and it didn't seem to work with my PC control pad.