I'm also looking at doing Law (specifically Arts/Law), and I've done some research, and here's my opinion. If I'm wrong on anything (which I may very well be), feel free to correct me, anyone!

I feel like the two best universities to choose from would be either Monash or Melbourne. I do agree that the Melbourne JD (Graduate Law Program) is slightly more internationally recognised and I also think between the two, it's a slightly better degree. However, you should also take the cost as well as location of these two uni's into account.
MonashIt's five years to complete the double degree with an average annual contribution of $7,300 which adds up to $36,500 for the entire degree. You finish after five years with a BA/LLB.
: Cheaper, less years, and if you get the required ATAR you are guaranteed (pretty much) to graduate with a law degree.
: Monash can be quite a commute for west-siders (or anyone not in the east-side). I personally also don't think that the LLB is as internationally recognised as the JD (but not by much).
Melbourne3 years of undergrad Arts ($5,442/year or $16,326 for the whole degree on average) + another 3 years for the JD (roughly $30,000 for the full degree). Total fees paid for Arts/JD is about $46,000 give or take.
: There's (I think) more flexibility with the Melbourne Model - more chances to pursue other interests and expand your skill set. Also, the location is amazing - so close to the CBD and right next to Lygon street. And you do finish with the JD. Also, it's much easier to get into Arts at Melbourne (ATAR: 88) compared to Arts/Law and Monash (ATAR: 98.4)
: More expensive. About $10,000 more expensive. Also, there's no guarantee you'll get into the JD. Last year, about 600 students applied for 200 spots. You need to sit the LSAT (which I've heard is brutal) and write a personal statement, as well as maintain a good undergrad weighted average. Unless, of course, you get an ATAR of 99.90+ which guarantees you a CSP place, in which case that's not a problem.
Note: These fees are all CSP fees. Full fee places (especially for the JD) are around three times more expensive. (So that 30k for the JD just became 90k. That's right.)