Lisk is planning to (other than providing blockchain as a service and allowing creation of side chains onto Lisk's main blockchain) launch an ICO platform for which you do not need coding to deploy smart contracts, and this is going to make it much easier for smart contract based businesses & ICOs to come up. So Lisk is essentially planning to bring many aspects of ethereum to the masses.

OMG is planning to launch an interoperable wallet platform, where everything with value can be transferred and exchanged, fiat, crypto, etc., payment wallets and gateways working in different countries can be connected. People can also launch their own wallets on this platform for payments.

Lisk is certainly undervalued at this time and will likely see a bump when they rebrand (should happen soon) and more people actually understand what Lisk does, but both would be good investments - both will still grow quite a lot more.