And I like another aspects that I did not anticipate: because of its isolation (by Oxford standards - it takes only 15-20 minutes to walk downtown), it is quiet and the student body, dons, and servants (still cringing at that term) form a cohesive community as is intended by the Oxbridge system (I will post on this tomorrow). It also has amazing grounds--twelve, beautifully-landscaped acres that border the river.
In short, I chose Lady Margaret for reasons that I thought made it a good place to live. But picking a college is not always or even often made on this basis.
Perhaps I should back track. Oxford and Cambridge are unique in that they each are comprised of multiple colleges, or mini-universities. Each college includes a library, dining hall, chapel, accommodations for dons and students, and gardens, often extensive (nothing compares to an English garden!). Colleges are often constructed much like a castle, with a porter's lodge that guards a large, castle-like gate which is locked at night (originally to keep students in than to keep anyone out). They are a place to live and build a community, but on an undergraduate level, even more. It is where undergraduate students apply (in England, students are permitted to apply to only one college in Oxford or Cambridge - so they need to pick wisely!), are "taught" weekly by "supervisors" (I will post on this later), and have their own funding and fundraising departments.
The last reason, funding, is a large factor for most, especially for graduate students, in picking a college. Based on reputations, the history of patronage by the crown, and, in more recent years, alumni giving, some colleges are wealthier than others. In Cambridge, for instance, Trinity College was founded by King Henry VIII and, because his empire was not toppled as other crown-established colleges (for instance, King's College), the endowment he gave to the college is still the largest endowment of any college in Cambridge--by a long shot.
Often, the more money a college has, the better able it is to attract prestigious fellows (faculty) and, consequently, students--especially at Cambridge. (E.g., Hermione from Harry Potter is attending Trinity this year, as did Prince Charles several years ago.) There is not an exact correlation--reputation of alumni and the architecture of the college (more on this later) also play a role in the prestige of a college. Prestige or ranking among colleges can be roughly correlated to whether the college was built from stone, brick, or cement. LMH, for instance, is a brick college, but as the first women's college, has fairly impressive alumni. It does not, however, have a lot of money for student "bursaries", or scholarships. If I was comparing college rank to U.S. socioeconomic swaths, I would probably--I'm still learning all of this--say that it would be upper-middle class.
I was unaware of any of this when I picked Lady Margaret. Yet I am extremely satisfied with my choice because it is where I feel comfortable and, thus far, am enjoying living. With all that I've said previously, that, ultimately, is what matters most.