I am currently working on making modulars from the ghostbusters firehouse set.
It will be one large building on a 32x32 base plate using grey and dark red bricks (and green at the back).. on two levels. The first level will be a youth centre with some arcade machines, pool table etc and a drinks machine as well as dart board (some of these are from the original set, some are custom) and the second level will be a nightclub with a drum kit, bar, some seats, an area to dance, a microphone and stand that could also double up as a pole for pole dancing (not sure about this one).
The other building will be mostly in tan and also use the brown pieces for a wood effect... also on two levels it will have a kitchen and living area for a single person on the ground floor (a television stand with ghostbusters playing) with bay windows and on the second level a bedroom with wardrobe and shelves.. maybe I will put a toilet and shower in as well.
It is nearly done actually and depending on the reception I might produce instructions.
Other sets that could be turned into modulars quite easily (perhaps with a few extra parts):
Arkham Asylum yes though you would need two of them to make it work.
Joker Manor : I Would like to see a MOC using two of them with the Joker elements removed... fully enclosed and not modular.
Ninjago City x 4 : Take two or four of these you could make a whole range of different modulars in a range of different colours.. lots of pieces leftover.
Tower Bridge: A guy called Inyongbricks has already done this really well and instructions are available.. really impressive.
