Not without a guide.

Second playthrough that is a pretty easy time to do it in though.

I fear there are still some very silly times in this list... I mean Banjo Tooie 10-15 hours? that is one of those times when someone rushed through perhaps, or knew exactly what they were doing... but I spent 30 hours on my first BT file.

The GTAs are odd too... I mean the stories can be completed much faster than that.

I still don't think this thread will be muh use as there are so many different qualifiers, some people saying times for first playthrough of a story, some for first playthrough of 100%... some for how fast they can do main story/100%, some for how long they have spent on the game in total etc etc.

@TWRoo, This thread is to give a general idea of how long some specific games are, that's basically the one thing that seems to be hard to find on the internet is how long a game is, hence this thread. Sure obviously all the games don't give a perfect estimate of how long a game is, but like I said, if a game seems off then post what time you have and I'll average out the time lengths that way the game length will be more accurate and in the future this thread will be more reliable (I'll add your time for BT).

If you have any problems with games (like I said a million times) just post what your time is and I'll average out the game length, instead of complaning about some games being off (obviously there going to be off, for now)

... and that's the reason for the 'Average' (first play through) 'Min' and 'Max' length you can play a game...

Crash Bash - 6 Hours

Ratchet: Gladiator (Deadlocked or whatever you call it)- 6 hours - 100% 14 hours

Does anyone know how long it takes to beat Knights of the Old Republic?

Star Wars: Knights of the Old Republic - 38 hours

(More if you want to do EVERY sidequest)

MGS4 -- 28.8 hours

Oblivion -- 60 Hours (FULL completion)

I'll try to get more game time figures tomorrow

Mega Man 9 took me 91 hours, 16 minutes to get 100% completion (all achievements). I'm pretty sure that includes some of the extra features (like playing as Proto Man), so I think 90 hours is a decent estimate.

60 hours to complete EVERYTHING in oblivion? or just the main quest

Because I have about 150 hours into it and I don't think I'm close to beating all quest and maxing everything.

Also, can anyone confirm that Okami takes 45 hours to beat?

Well this thread seems to serve a nice purpose.

I have to wonder where you got that 14 hour figure for Majora's Mask, though. >_o

Edit:

My contribution - Demon's Souls

Playthrough 1 - ~100 hours (though admittedly I was standing in the Nexus doing nothing for longs periods of time lol)
Playthrough 2 - ~45 hours
Playthrough 3 - ~20 hours and counting!

I'd probably say an average playthrough is 60 hours or so for a first timer.  In order to Platinum or 100% everything, you're going to play through the game three times at the very least (retaining your data each playthrough via New Game+).