Lived at Howitt 2 years, going to be staying a 3rd there next year. Briggs and Jacko; it is true that they are much less social than the 'old' halls - go there if you don't really care for parties and general socializing around the hall on a daily basis, but you want a 5 star, fully contained room which you pay a fortune for (I think its about $1300 per month). The old halls have many traditions and a fully developed culture having been around a lot longer, the fact that they are not self contained means you have to cook together and share bathrooms (Unless you opt for an ensuite room), but this means you literally cannot get away from being social, even if you don't go to the awesome parties or the weekly suppers/common room gatherings. The rooms at 'old' halls look like prison cells without stuff in them, but once all your stuff is in there it looks significantly better. Bathrooms are multi gender and pretty nice - kitchens, laundries and bathrooms are cleaned daily. Keep in mind all 'old' halls were built in the 60's and look like crap basically, but you learn to love it, plus the social atmosphere and people easily make up for that.
For the old halls I'd recommend any except Normanby (It's socially dead because it's physically isolated and for some reason they never join in with other halls stuff), Howitt is a high rise building and very unique in that sense (Thats why I love it, it makes the social life unique too because of it's physical layout, each floor - 20 people or so - is a community). Deakin has the biggest rooms and hence the smallest population, roberts and richardson are pretty much the same and seem alright, same with Farrer except for some reason people from farrer (farrets) always seem to be the most reckless lol