Yeah, I enjoyed TW3's weather variations a lot. I also liked little touches like a different choice of music during the night: I think the first game where I noticed that happening was Gothic 3, and it also really adds to the overall atmosphere.
TW3 had some fairly obvious things such as noon-/nightwraiths that could only be tackled during certain hours, as well as various quests ("meet me at midnight by the crossroads", sort of thing) but sometimes it's the apparently small changes to the ambience that make the big differences.
