It may have changed, but Melbourne University had a strong functional programming component at one time. I think personally its the more "computer science" focussed of the choices. The rest are great, but its moving into Networks, Engineering, UI, design, <other>
Monash did more engineering-communications focus because the Telecom Australia Clayton Labs was next door.
RMIT is very pragmatic and design focussed. Swinburne also.
If you want gang-of-5 it has to be Melbourne. If you think you're an engineer it might be Monash. If you want to walk into a job then any of them but RMIT and Swinburne drive hard to make it happen.
I've worked with people from all 4 over the last 35 years. They were all fantastic, skilled, and nice people.
Melbourne is a very urban/urbane experience. It has colleges, and it has Queen Vic Markets and BoHo suburbs like Carlton and Brunswick close by. RMIT is very inner-city vibe. Its architecture is cool (melbourne colleges include ones designed by walter burley griffin) -Monash is a classic campus, it happens to have a ducting tunnel big enough to drive a tractor around, but its more suburban. Swinburne is a bit of both.
Latrobe is also good but more distant.
I want to add that going to university now is very different to my own experience, because I got a full grant, and I walked into a degree with less than 10 students by the end because compsci was a "new" subject. The social aspects of college life are different, the cost of study is different, the mixture of study and work, expectations, class sizes, tutorials, expectations on pre-entry: It's really hard to offer help from my distance and you should preference anyone who responds clearly saying they are closer to 30 than 63.