I just stumbled across this thread.
I'm surprised nobody has suggested the Beyerdynamic DT-770 Pro. For a really bass heavy sound, I suggest coupling it with the Fiio E11 amp - this combination will rival the Crossfade LP any day of the week. (and yes I have the v-moda's as well)
I've got a new amp coming in the post so i wanted to go back to my Beyerdynamic's for a few days and WOW that E11 adds almost too much bass when you put the EQ on 2 (there is 0 for no bass boost, 1 to boost the sub-bass a little, and 2 which boosts the entire bass range of frequencies A LOT)
I have the 80 ohm version and suggest you do too. Do not bother with the 32 ohm edition, in my opinion, as you are getting lower build quality and less comfortable earpads.
The isolation is some of the best you will find in closed headphones that are not noise cancelling. It is superior to the v-moda's (like i said i have both and for the last few months before this week the v-moda's were my daily headphones).
Plus if you have ever found your v-moda to be a little uncomfortable, the earcups on the DT770s are much bigger, so that won't be a problem for you anymore.
For bass heavy noise cancelling headphones, i can strongly reccomend the PSB M4U2 headphones. Expensive, but for the amount of versatility they have, they are great.
So yeah, Beyerdyanmic DT-770 Pro + E11 headphone amp - that's my reccomendation.
I live in Australia and those two would cost me about $320, so if you are in the US or europe you should be able to get them both for under $250.