using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        List<Issue> DOCCCOIssues = new List<Issue>()

        {

            new Issue("A"),

            new Issue("B"),

            new Issue("C"),

            new Issue("D"),

            new Issue("A"),

            new Issue("A"),

            new Issue("D"),

            new Issue("A"),

            new Issue("C"),

            new Issue("C"),

        };

        var query = (from c in DOCCCOIssues//.IssuesModels

            group c by c.Comment into g

            select new

            {

                Comment = g.Key,

                Count = g.Count()

            });

        foreach(var x in query)

        {

            Console.WriteLine("{0} - {1}", x.Comment, x.Count);

        }

    }

}

​

public class Issue

{

    public string Comment {get;set;}

    public int SomeValue {get;set;}

    public Issue(string comment)

    {

        this.Comment = comment;

    }

}