I went into this game ready to hate it because it, on the surface, looked bland and not very compelling. However this game grew on me faster than any of the others and it's still my favorite in terms of storylines. I think the only thing that was lacking was the monster design (or rather the monster sound effect design).
Other than that, this game was absolutely amazing. As previously mentioned, getting you attached to the room and then pulling all of that security away from you and turning it into a place in which you felt extra-vulnerable (no weapons and reduced mobility in 1st person mode) was a stroke of genius. Also the spiraling downward path with all the 'exhibits.' That is still one of my favorite moments in the series.