There are over 330 different student groups on campus, so it's hard to say what's most popular. There are lots of sports, although only a few are Division I, religious groups, cultural groups, singing and theater groups, literary groups, a yearbook, and so many others. There are twenty-seven fraternities and five fraternities (with another joining campus next fall) with about 40{4a082faed443b016e84c6ea63012b481c58f64867aa2dc62fff66e22ad7dff6c} of males in fraternities and about 30{4a082faed443b016e84c6ea63012b481c58f64867aa2dc62fff66e22ad7dff6c} of females in sororities.
I'm in a start-up a Capella group called the Remainders. We just got started last semester, and after a rough semester, during which we lost all but one male, we just had auditions and will be resuming with four males and four females. We are low key compared to other a Capella groups on campus. We don't compete or perform, although we might randomly show up in Lobby 7 to sing one day. We sing mainly old pop/rock, Disney songs and musical stuff.
Some people leave their doors open, some don't, sometimes it doesn't matter. People are generally friendly and upperclassmen are usually available to help other students on psets.
If you're interested in something, you'll attend, like at any other school. Crew is one of our Div I sports and the Head of the Charles is well attended. There are lots of theatrical productions and they are well attended, as are the musical concerts like those of the Wind Ensemble, Symphony Orchestra, Concert Choir, etc.
Dating scene, I assume, is like that of any other school. Dorm-cest, floor-cest, hall-cest and wing-cest (dating someone you meet through where you live) are all frowned upon. A lot of the time you'll spend with your significant other will be doing work, so it's helpful to have similar schedules. Unfortunately, weekends are frequently spent catching up on missed sleep, but there are always things to do, so going out is definitely possible.
One of my closest friends, I met through a pre-orientation program we both did. Another was in all my classes this past semester, but I met him on a CCC retreat about two months into the semester. We were both in Concourse, an alternative method of teacher freshman, where all your classes are in one room and there's a lounge next to that for doing work and having tutors come help. Another I met randomly in the dining hall of my dorm during an orientation meet and greet, and another I met through her (they'd been in a pre-orientation program together as well).
2am Tuesday night, I'm up doing my 8.02 pset with my boyfriend and friends in the lounge below where I live and working on 6.01 (CS) online homework, plus possibly editing an essay for my writing class.
Hacking is a big part of MIT culture. "The word hack at MIT usually refers to a clever, benign, and "ethical" prank or practical joke, which is both challenging for the perpetrators and amusing to the MIT community (and sometimes even the rest of the world!)." Walking around campus and seeing candles on top of the dome on Building 7, or seeing Guy Fawkes masks covering the faces of statues and on posters down the Infinite on November 5 or giant scrabble game on the side of the MIT List Visual Arts Studio is just a part of life at MIT.
Ring Premiere, when the sophomore class Ring Committee presents their year's Brass Rat (class ring) is something you don't want to miss (if it's your class).
"Work hard, play harder." is one of our mottoes...also "Play, Work, Sleep, pick two." Since there are so many fraternities and other student groups, weekends, and even weekday nights, are packed with different things to do, including party. On any given weekend night, there might be at least three different parties, plus movies presented by the Lecture Series Committee, speakers, and other events.
Last weekend, I watched a movie with some friends on Friday, Saturday I woke up early and went to Shaws with a friend to buy groceries, came back and ate breakfast at a dorm study break, held auditions for my a Capella group for five hours, went back to my dorm and tried to get some work done, then hung out with my boyfriend. Sunday, slept in really really late, then went to a Capella rehearsal, came back and did work until about 4am.
Saturday nights, you can go watch a movie, you can go into Boston and wander around, you can see a concert or recital or performance by some group, you can chill with people in your dorm, play video games, or get sleep (always a good choice).