If you are absolutely sure that HTTP is the protocol you want to use and you want to embrace it as an "Application" protocol, not just a "Transport" protocol then something like ASP.NET Web API.
If you building a service for your servers in your datacenter to talk to each other then seriously consider WCF.
Whether to do REST is a completely different question. Will this service last for many years? Will it have many different clients? Will some of those clients be out of your control? If you answered yes, then it may be worth investigating what benefits the REST constraints can bring.
