There are so many projects now that I don't know if anyone is already working on or has a token sale being planned for these, but the best ones I could think of are:

* using Town Crier or some other oracle that utilizes trusted hardware to provide authenticated online bank transfer statements, for a Dapp that enables trustless fiat <-> ether exchange. This would be very ambitious and very costly in resources and time - possibly over a half a decade to really get it right.

* online markets, though several are being worked on

* a Dapp for trading GPU time for game-time tokens, and using the GPU resources to generate procedural worlds, fauna and plant life, like a much richer and decentralized version of No Man's Sky. With the GPU resources, the fauna and plant-life could be generated through evolutionary processes, to make them much more compelling and realistic.

* a privacy-focused payments Dapp, especially one that utilizes the new functionality that will become available with the release of Metropolis, which will make both ring-signatures and zk-SNARKs possible.

* a payment channel Dapp for use in a Lightning Network implementation