Here you go, gentlemen. Syscoin seems to have a large edge on the race for a decentralized market mainly due to the fact that everyone else sucks:
Bitbay: Closed source! Moderated! Enough said!
Axis Mundi: Linux only. I really don't have the patience to get this crap to work but I am no Linux guru. This marketplace has no chance of ever going mainstreem with average Joe. Has arbitrated crap-escrow.
NXT Freemarket: Massive pre-issued coin, will never use on principle alone, closed source at launch, NXT users can go f@ck themselves, desktop version not working due to "changes in NXT", web version not working either. Has arbitrated crap-escrow.
Openbazaar: Not anonymous. Does not work over Tor. Automatically eliminated from consideration.
Bitmarkets: 2-party escrow, works over TOR, but who cares, its OSX. Automatically eliminated from consideration.
Shadowcash: Has been de-anonymized in the past but fixed the bug... growing pains? lead dev doesn't seem very intelligent, probably why they still have nothing workable after 2 years? Might have potential, the only other possible competitor to Syscoin IMO but I have yet to actually see anything. Shadowmarket to be release by the end of 2016? Doubt it. Has superior 2-Person escrow. Is the core dev really a 14 year old freckle-faced fat kid???
In theory dde sounds better yes but in reality it is not.. it hinders growth as it creates a higher barrier of entry. Once network effect is achieved I can always implement an option to do trustless escrow with deposit although there needs to be a backup plan to let buyers extend the bomb tx... thus we implemented a full rating system linked to aliases that complements the escrow to get people using it safely. The correct business decision is currently AE but DDE is on the radar long term. Any system using dde from the get go now will have harder time taking off.