Hey; I went from 2014 to 2018 and was a student ambassador during my time at Exe. Met lots of people in first year, so feel like I have solid experience.
(for reference, east side of campus = closer to town and more accessible. Makes a big diff over the year, trust me)
Holland Hall - the most expensive but by far the best in terms of quality and location on campus. Not a small campus either - so location is important. Has a stereotype of being "posh" or "aloof" - generally people with quite wealthy parents live there... but not always the case. It is catered
Mardon - Next to Holland Hall, great location. Catered. A bit cheaper. Very sociable and lots of parties within; there is a communal/family atmosphere in Mardon. Convenient tennis court opposite. Watch out for the shared rooms, a lot of people don't like sharing a room with another person...
Birks Grange Village - I stayed here in my first year. Plus side is that it is VERY sociable as it has a huge number of flats. Blocks A - Q (!) from what i remember, so hundreds of people. A village in itself, very busy and lively. Mix of catered and self-catered. BUT I would actually advise against it. I did not enjoy it. It is at the very bottom of a steep hill (google "cardiac hill Exeter") which you will have to face multiple times every day. It has a very steep incline, and imo is purely unenjoyable and exhausting. It is also on the West side of campus, meaning that the walk to town is LONG (about 30 minutes...), with no clear bus connections.
Lafrowda - self-catered, closest to the centre of campus (the Forum), right next to the student night club, very easy to access town, in the 'middle' of everything. Very sociable and lively, lots of parties. Important to note distinction between "old" and "new" Lafrowda - the "old" being (ostensibly) very dingy/poor quality, albeit cheaper. "New" Lafrowda blocks are newly built and much nicer. Big communal areas in both. "Old" and "New" Lafrowda are situated next to each other. Great vibe there though, near everything and tennis courts v close
Pennsylvania Court: The Holland Hall of the East side of campus, with slightly worse views and lower prices. Excellent location to get to campus and town. Similar reputation to Holland Hall, but to a much lesser extent
Rowancroft - Same location as Pennsylvania Court. Worse quality. Cheaper. Shared rooms. Sociable. Would lean towards avoiding
Duryard - Nice, but miles from campus and town. On the far north-west side of campus. Avoid imo. Sociable enough and nice flats
Moberley - A renowned reputation of being the absolute pits. Have heard it referred to as an asylum/refugee camp... it is really bad quality and dirty (at least this was the case in 2014). Also far from town and campus (in a similar location to Duryward). Lots cheaper to make up for the quality. Avoid imo
There are lots of other smaller ones which I will not go into detail as it would take too long, but these are the main ones. Smaller ones are generally for quiet people (such as St Germans).
If could go back in time, I would have stayed in Lafrowda, Holland Hall or Pennsylvania Court
Any questions whatsoever, let me know. Exeter is a fantastic place and you'll have lots of fun, without a doubt. Beautiful campus too!