I haven't been in a DJ lounge yet, except for the one at ADL (I was SC running with a WP buddy and we decided to, with the consent of the lounge receptionist, to have a little "tour" of The Lounge at ADL). I thought that ADL The Lounge was OK, but compared to the expansive ADL QP it seemed very boxed in and a bit sterile.
As far as domestic lounges go, my votes go to the ADL QP due to the size and comfort. Probably a little biased given that ADL airport itself already looks amazing, but them's the facts. MEL QP and J Lounge come in on second.
SYD T3 QP (not J Lounge) and PER QP have nice views, the latter with a full view of the runways. They have a tendency to be quite crowded, though. In the case of the PER QP, it's a low ceiling so when it's busy you can really hear it.
As for international lounges, on the QF QP side of things (apart from ADL QP which caters for both kinds of traffic) I like BNE I QP best. It's a relatively small lounge, but a great view of the terminal and further of part of the tarmac. The architecture of BNE I also gives a nice airy open feeling. Only fault is that BNE I and BNE D QPs both have pathetic showers (I know we restrict water use, but this is ridiculous...)
SYD T1 QP isn't the greatest offering that QF can give for it's oneworld and QFF traffic in its major international hub, but considering other overseas lounges I've seen, heard of or been in, I think it's actually quite a nice lounge. Good showers in SYD T1 QP (and F Lounge, of course).