I'm not taking of using any glitch of course and if you focused solely on the trophies I guess you could do it in 100 hours or so. But the game has a way to drag you onto sidequests and just exploring
For leveling otherwise it all depends what you are doing, I am lvl 44 after 76 hours..
The main quest in itself seems pretty fast.
What takes a while is the 20 dragon shouts and the 50 dungeons cleared...( and the thieves guild stuff takes a lot of time too).
Edit: it could easilly be 200 hours if you decided to forego fast traveling too. I hated walking at the beginning but now that I have Shadowmere I am almost temped to ride everywhere ;)
PS : One piece of advice by the way, do the imperial/stormcloak questline early on as I am doing them late in the game and it's the first time I really experience bad lag. It would have been better for me to do them early on when my save file was small..
PS3-Xbox360 gap : 1.5 millions and going up in PS3 favor !
PS3-Wii gap : 20 millions and going down !
