last time i played it was 39 hours, 44 minutes. the time before that, however, i was done after 22 hours, 19 minutes. wierd.
About 45 hours the first time, and I did pretty much everything except the bounty hunter missions and Pazaak, which I didn't bother with at all.
Also, I had to defeat Malak the hard way, as I didn't have any kind of force power to kill all his captured Jedi that he used to keep upping his life
On my current playthrough I think it took me about 10 hours just to do Taris.
First time i played i spent roughly 93 hours on it because i fell asleep twice on Taris and kept watching the views on Tatooine and Dantooine. Plus i had to investigate every nook and crannie. Especially the crannies.
The second time was about 60 hours as i found more crannies. The views were amazing for me though, had never played a game like it. Still hav'nt. Well, apart from a "Kotor 2" game but i don't like those type of games. :P
My first time through, I missed about half of the game, and it still took me 27 hours and 43 minutes. Second time through, I did everything, and it too me 32 hours and a few minutes. 3rd and on, i can do everything in about 11 - 13 hours, Taris takes me 50 minutes, if I skip the cutscenes and dialouge.