Retrieve OptionSet Text in CRM 2011 using C# in Plugin

Retrieve Normal(Local) Option Set Text

// Get Normal option set Text

string optionsetText = entity.FormattedValues["new_optionset"];

 or

string optionsetText = entity.GetFormattedAttributeValue("new_optionset"); 

Retrieve Global Option Set Text 

// Retrieves Global Option set Selected Text

        // Parameters: 1. Entity Name   2. Service  3. Global Option Set Name   4. optionset selected value

        public string GetOptionsetText(Entity entity, IOrganizationService service,string  optionsetName,int optionsetValue)

        {

            string optionsetSelectedText = string.Empty;

            try

            {

                RetrieveOptionSetRequest retrieveOptionSetRequest =

                    new RetrieveOptionSetRequest

                    {

                        Name = optionsetName

                    };

                // Execute the request.

                RetrieveOptionSetResponse retrieveOptionSetResponse =

                    (RetrieveOptionSetResponse)service.Execute(retrieveOptionSetRequest);

                // Access the retrieved OptionSetMetadata.

                OptionSetMetadata retrievedOptionSetMetadata = (OptionSetMetadata)retrieveOptionSetResponse.OptionSetMetadata;

                // Get the current options list for the retrieved attribute.

                OptionMetadata[] optionList = retrievedOptionSetMetadata.Options.ToArray();

                foreach (OptionMetadata optionMetadata in optionList)

                {

                    if (optionMetadata.Value == optionsetValue)

                    {

                        optionsetSelectedText = optionMetadata.Label.UserLocalizedLabel.Label.ToString();

                         break;

                    }

                }

            }

            catch (Exception)

            {                throw;

            }

            return optionsetSelectedText;

        }