With regard to EC, it's supposedly very different depending on the floor you live on. I don't actually know which floor is what except that 5E isn't "normal".
i feel like it would be unfair to only mention some of the dorms. general stereotypes of the others -
mccormick - all girls, nice facilities, really convenient.
baker - more "social" (I don't really know what that means either). They have really good stirfry at Baker Dining.
BC, New, Next - they're similar enough to each other to be mentioned simultaneously - people are very friendly in general, people like to complain about far Next/New house is.
MacGregor - all singles, thus supposedly more "antisocial" although it again depends on the floor.
Simmons - quiet, new, more isolating.
Bexley - they have a little "antirush" at the beginning of the year to scare off freshmen. Bexley is supposedly east campus in terms of culture, but the people I know there wouldn't fit the stereotype.
and please also consider the FSILGs because they are certainly another viable option and are probably not what you expect.