Mmm, I own every Silent Hill game, even the more...obscure stuff. Also I think it's implied that SH2 is after 1, if I recall correctly dates are mentioned in both games. Not to mention 3 has to be after 1, given it's Heather. 4 I'm not entirely sure about, though I believe previous games are paid homage to in a way that would mean that 4 is surely after 2/3.
Just got off Tribes:Ascend. Played for 6 hours straight, and now it's almost 7am. Sleep time for me.