I've never tried glitching, so without it I'd say about 6 hours... not too sure though cuz I've never actually timed myself. I might pull an all-nighter for a speed run some day to find out. I've actually been meaning to for a while now..
8 hours 6 minutes and 6 seconds to beat the game. This includes beating the game from start of the game to the final blow on Ganon. This also includes all cut-scenes including the beginning cut scenes, and the cut-scenes after you beat each dungeon. It also includes getting every Map, Compass, Dungeon Item, Optional Dungeon Gerudo's Training Grounds where I got all 9 keys. Stopping by all 6 great fairy fountains, getting 3 bottles, No using any glitch to bypass anything in any dungeon, or any other area.
sadly i think my fastest time is about a week
but i havent really tried and thats with only like one or two hours of game play a day
if that. so in total, about 7-10 hours?
ive never actually timed myself tho
but that is a goal for me one day is to see if i can beat the game in one sitting
Well considering I haven't played OoT without shooting for a 100% since I got the game in 98 I'd say my run time isn't very fast, but if I had to put a label on time maybe 11 hours without a walkthrough.
One night I did a start to finish run in about 8-9 hours. It wasn't a "speed" run since I wasn't going out of my way to shave time, but I went through the entire game in one sitting from 10 at night til around 4 or 5 in the morning. I didn't initially plan on doing that, but by the time I finished the Water Temple I figured I might as well go all the way to the end.