First of all I would love to see an Fiat-on-ramp on Steemit.com itself. Whether this would be established by a third-party developer like e.g. EasyDex or from Blocktrades doesn't matter, but it would provide such a huge economical improvement if we could have a Fiat exchange available right on the Steemit.com site.
Than other exchanges like Coinbase and Bitfinex would be great as well!!!!