Hi Daniel521, well it isn't genre specific as a hard rule, but I think the target audience will be the biggest factor. If the music is intended for a younger consumer base, i.e rock, rap, techno, house, dance you can bet that it will be so compressed that the dynamics are long since gone. However, I have noticed that if the music itself is less complex, not to many elements, and mostly generated samples then even if the music is mastered loud, it might still have some fairly good dynamics left. Here is the waveform for a Chemical Brothers track I like to use as a test track, the song is called Come Inside.
You can see that it has certainly been mastered hot, but because the music is not that complex there are still some dynamics left (or so I interpret it as being due to this). Even when this song gets busy it sounds okay. Sure you can tell it is compressed, but it isn't a total green wash like the Green Day track I posted. Here is the amplitude analysis:
The total RMS Power shows that it is actually a moderately-loud track. And notice that we have thousands of possibly clipped samples, but the track actually sounds good. I have listened to this with a nice DAC from Audiolab and through my Auditor which is designed for studio use and the track sounds good. Based on what I have read, but sadly do not understand as it is hyper-complex, clipping can actually be dealt with in such a way that many end user DACs and analogue stages handle the clipped signals well enough that it doesn't sound clipped.
In general, from what I can tell, if the labels producing the albums don't feel it must be loud, they don't seem to care and it seems the recording engineers are allowed to actually craft recordings. Jazz, classical, better quality progressive music such as Peter Gabriel seems to not suffer from hyper-compression death. I can't imagine you could find a single well mastered rock or hip-hop, rap album anymore, but I could be wrong. At one point the labels decided louder was better and nobody cared about fidelity and dynamics any longer, or at least not young people. It has been good for me as I have by necessity had to branch out even further to find music that I enjoyed, and that sounded good. I am actually going back in time now and listening to some of the older recordings from the 70s and 80s that I used to think were dull. Now I realise they seemed dull when compared against hot mastered albums, but when I listen for actual dynamics, hands-down the older recordings actually kick butt. I am constantly trying to find new music to listen to and I wish I could offer more suggestions, but these opinions of mine are all I have. The facts are of course, subjective, but I think where dynamics are concerned more is better.
