It's funny, but I almost always preferred to keep my human appearance, so I wouldn't call myself really familiar with all these scenes...
Thus, for me, almost the only possible answer is Bimbo Liquor, and not, say, Naga or Bee, although there are interesting scenes there too...
P.S. Some scenes I find very unexpected, but nice.
Although due to the rather high requirements for them, some scenes are VERY rare. So, for example, I accidentally found out about a longer dream scene on the tenth day at Corruption 50+... what a pity that by the time I found out about the full scene, I had practically lost interest in CoC1...