Denon D2000/D5000 if you can find them at a nice/attractive price (but the treble on the D2000 is harsher...). They are very comfortable and deliver a lot of bass/sub-bass.
Q40 you already have...
V-Modas M100s DO deliver massive amount of controlled bass and actually they isolate 'Ok' but THEY ARE NOT comfortable... (at least not to my ears! :-()
Ultrasone Signature DJs. Have NOT tried these, but if they are bassier than my Ultrasone Signature Pro (which to me, they do apply a very decent amount of sub-bass!) then you will be good.
Of course, you can always look into the Sony XB line...
Regarding the DT770, I had the 80 Pro version (32 Ohm I believe) and although comfortable, I didn't really like them that much. (i.e. I prefer the Q40s over it even though they are not as comfy). But, as always, YMMV and you might actually like them.