Web service framework for .Net

Hi

I have been asked to review and select the best Web service framework for .Net based on criteria such as cost, ease of coding, security, and selection of protocols (SOAP, REST, OData etc.). The company's Salesforce instance is the central source of data, so that may also be relevant in the choice. Does anyone have any recommendation for this selection? We have not even started to look at possible options yet...I just need a shortlist of the current best of breed Web service frameworks for .Net.

Thanks in advance