I would give this to IDEX. It has real volume and the exchange has liquidity, despite being a DEX. I do not think you need to pay any fund to get listed on IDEX, inasmuch as your project worth it. Therre are lots of projects that have been able to make good headway to other good decentralized exchanges,
Another thing about IDEX is that, community members can by themselves apply for listing on IDEX.
Assuming the said digital asset is Ethereum based, My best bet will be Idex. Idex is not only one of the most genuine exchanges but one of the most natural exchanges when it comes to trade volumes. Idex has real traders and rarely do you find wash trading or bot trading on their exchange. What you see is what you get.
But IDEX is designed to be an Ethereum assets exchange. It means that only tokens built at top of Ethereum can be added to IDEX and they only can be exchanged to ether. Just like EtherDelta and ForkDelta. This should be the right option for op if the coin is an ERC20 token and don't yet having a considerable trading volume as the project is still under-developpement.
OP, as mentioned above, good projects will reach exchanges without even contacting them. If you really want to contact some of the major reputed exchange in the market then please don't hesitate to check the link in my signature which refer to BestChange platform, a platform dedicated for exchanges searchers to choose the best platform according to their exact need of pairs .