using System;

using System.Collections.Generic;

using System.Linq;

using Newtonsoft.Json;                  

​

public class Program

{

    public static void Main()

    {       

        List<string> list1 = new List<string> { "test", "otherTest" };

        List<string> list2 = new List<string> { "item", "otherItem" };

        List<string> list3 = new List<string> { "value", "otherValue" };

​

        var list = new List<List<string>>() { list1, list2, list3 }

            .Aggregate(

                seed: Enumerable.Range(0, list1.Count).Select(e => new List<string>()),

                func: (prev, next) => prev.Zip(next, (first, second) => { first.Add(second); return first; })

            )

            .Select(e => new

            {

                a = e.ElementAt(0),

                b = e.ElementAt(1),

                c = e.ElementAt(2)

            });

        Console.WriteLine(JsonConvert.SerializeObject(list, Formatting.Indented));

    }

}