On average, I get through Silent Hill 2 or 3 in about 4 hours. I'm not sure how long Origins took, but it couldn't have been much more than that, if even. The Room takes me considerably longer, for whatever reason. I've only played through Homecoming once, with a few hang-ups 'cause I couldn't figure out where I needed to go. I've also only beat Silent Hill once, and it took 25 hours, because we didn't have a memory card, so we couldn't save or turn the game off, and we took regular breaks to go to the store / watch movies / sleep / etc. while leaving the game paused or on a menu or something. Haven't beat Shattered Memories yet, 'cause I don't own a Wii, so I don't have much chance to play it.
So, I'd say either 2, 3, or Origins is shortest.
And for longest... I don't have sufficient data to draw a conclusion.
For shortest, it's a tie between Shattered Memories and Homecoming. The latter because I've gone through it 4 times now, so I know where everything is and how to beat it quickly and efficiently. The former because...well...it's short. 0rigins actually had an okay length.
The longest for me would have to be Silent Hill 3, although 4 may be a contender because of the repeat worlds. >_>
Yeah, Origins took me only 4 hours my first time through. Most of them take me about 7 my first time, though my record for SH2 is 1:19. The longest I would say is SH4, or Homecoming. I'll see about SH4, I think it takes me a half hour on average for each world, which makes it roughly 6 hours total now.
IMO the first and original Silent Hill is the longest SH. I've never played it through to the end but I've just passed the Lakeside Amusement Park and the clock of the game says about over 11 hours! Now I'm at the hospital again (third time) and some strange noises surround me. Hrr, I'm so scared... The atmosphere of the game is sooo depressing!
Silent Hill: Shattered Memories must be the shortest one. In my first playthrough the game was over quickly. An excellent game of course but too short.
for me as i remember the shortest was silent hill 1 and silent hill origins and the longest was silent hill 5 homecoming and silent hill 4 and silent hill 3 and silent hill 2 as well! i still never played silent hill shattered memories yet! i have a baad PS2~i must fix this sooner or later xD! ^_^
Shortest is easily Origins. Don't see how any other game could qualify for that position. Maybe SM would be the runner up simply because the lack of gameplay and simple puzzles make the game more "streamlined" with less stuff holding you up and taking your time.
Longest would probably be Downpour and Homecoming as the runner up.
Shortest is Origins, but could also be SH2 if you count the BFaW scenario lol. You can finish that in like 20min. But for the main scenarios, Origins is the shortest, and Downpour is easily the longest.
Not sure which one is technically the shortest, although I'd assume Origins. For me personally SH3 took the shortest to complete the first time through. It was pretty quick. Homecoming and SH1 were longest for me. Although to be honest, SH1 was the only one I did entirely myself without ever consulting any guides or walkthroughs. I suck at puzzles, so I got hung up a lot.