The Joe Grado HP1000 is one of my all time favorite dynamics. It has a delicate quality only seen in some high end IEMs curiously enough, yet it still has the fuller sound of open headphones. With some mods they can be super awesome. Even unmodded however I'd take them over many other new flagships today.
The John Grado PS1000 gets some flack, but I think it's pretty good when paired with the right amp (like the ZDSE). I'd take it over a T1. Really prefer the older style cups to the polished chrome "rims" they have now however.
The John Grado PS-1 is more or less on the same level as the PS1000. Does some things better, some things worse.
The PS500 is a fun headphone.
Vintage RS-1 and SR320 are surprisingly smooth sounding.
Can't stand most other contemporary John Grados however.