Best upgrade from my senn hd558

[aftalifex]

I currently have the sennheiser hd558 running through my jds labs objective DAC and little dot mkiv amp. I would like to get headphones that will use the power of my little dot more to its potential. My preference of sound is pretty flat but I want a boost in bass compared to my 558s. I love my soundstage in these bad boys and would hate to have to give it up for higher resolution headphones. I hear the hd600's are great but I want another opinion. My budget is pretty open but I can't quite afford the LCD2 so i would like to keep them well under the $1000 mark. Any help is appreciated!

 

[KG Jag]

Look at the AKG K 7XX and 712.  If you are OK with a bright can, the DT 880 is excellent--see:
 
http://www.head-fi.org/t/634201/battle-of-the-flagships-58-headphones-compared-update-audeze-lcd-2-revision-2-6-4-13#user_DT880

 

[Youth]

Soundmagic HP200, DT880, HE-400i, T90, HE-560