On my main character (he was the first character i ever made, and i made him back in June 2012) i have played for 1568.3 hours (i have an app on my iPhone that you link with you're PSN and it counts how much time).
298 currently on my forsworn.
However since I play on the PC and often play with Steam set offline, it doesn't track all my hours. Over all my characters I am sure I'm over 2000.
Wolf my sword and board DG character has 125 hrs, Zariea my thief has 150 and Cara my new character has 37. Over all my characters probably well over 3,500. My longest played character was Derik Imperial battlemage with 500+ hrs. ( I don't remember the exact mumber)
Michaelpk is gonna blow people's minds with the hours he's got.
with my first character I had 456 hours....then the MQ got bugged and I cried for a whole day
no clue :/ I'd wager 300 or so (for just one character, ive made many)
On my current character, I have 114 hours invested. I'll probably get another 20 or so out of him before his adventures in Skyrim come to an end and he returns to Valenwood for a nice quite retirement
My longest playthrough was 176 hours, this was before any DLC had been released.
Total played since 11-11-11...I have no clue since I always play offline. If I had to venture a guess, I'd say probably close to 2000 hours.
On a single character? I have no idea.
Altogether, 323 hours.
I've spent about 900 on one character, he was my first character that I made last January when I first got the game. I have another character who I've spent about 300 hours on, and it gets progressively lower after that.
I've got about 700 hours on my one and only (so far) character (I just started playing in June). I foresee at least 700 more, maybe even a whole lot more than that now that I'm playing on PC with mods.
I have no way of knowing exactly. But I'd guess the longest amount of time I've spent with any one character is 400 hours.