The third one is Comparative Literature.
I assume you know a pre-requisite for any of these courses is having accelerated at least 2 units of an HSC subject in year 11 (or previously, etc)?
I do Philosophy. It's pretty good. The workload is only as heavy as you want it to be and it scales pretty well but not as well as it seems [state average is 40/50 or so per unit (whereas average, like geog, is 25/50 and 4u maths averages at about 42-43/50 from year-to-year)]. There are a LOT of smart people who do it though, I'm in it with people who have done 13 units, etc. So dont think its going to be easy to beat the state average. I guess its because some of the people arent as spectacular at the bread and butter subjects as maybe youd expect. It's an interesting environment.
The residential schools (there are 3) are at UNSW for us Philosophy people (Comp Lit is at Macquarie I think and I think Cosmo does a big road trip out west). Philosophy is done by correspondence through UNE in Armidale and the others are done through CSU.
If the subject interests you and you think you'll go well enough in your accelerated subject to get in (it's not that hard if your school report is reasonably good too) then go for it!! They are a lot more 'casual' than the run-of-the-mill HSC subjects.