I lived in Rains for three months while I did an REU at Stanford. Rains is probably the most social housing option, so I would lean toward it for a two-bedroom option. I personally thought Rains was nicer than EV overall and preferred the more social atmosphere. I didn't visit Lyman, mainly because Lyman is way on the other side of the campus from all the other housing. The only reason to live in Lyman is if you're engineering and want somewhere relatively quiet and close to lab.
I'm personally planning to live in Munger. Sure, it's more expensive, but damn, it's nice.