Much better than using the built-in command line argument parsing.

CommandLineArguments.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

public static class CommandLineArguments {
    /// <summary>
    /// Parses command line arguments.
    /// </summary>
    /// <param name="arguments">String containing the arguments. Uses Environment.CommandLine if null. Does not allow escaped double quotes.</param>
    /// <returns>List of arguments.</returns>
    public static List<string> Parse(string arguments = null) {
        return Parse(false, arguments);
    }

    /// <summary>
    /// Parses command line arguments.
    /// </summary>
    /// <param name="allowEscapedDoubleQuotes">If true a sequence of \" between double quotes will be a single quote.</param>
    /// <param name="arguments">String containing the arguments. Uses Environment.CommandLine if null.</param>
    /// <returns>List of arguments.</returns>
    public static List<string> Parse(bool allowEscapedDoubleQuotes, string arguments = null) {
        Regex regex;
        bool removeFirst = false;

        if (arguments == null) {
            arguments = Environment.CommandLine;
            removeFirst = true;
        }
        List<string> args = new List<string>();

        regex = new Regex(
            allowEscapedDoubleQuotes ? "\"((\\\\\"|[^\"])*)\"+|[^\\s]+" : "\"([^\"]*)\"+|[^\\s]+",
            RegexOptions.None
        );

        foreach (Match match in regex.Matches(arguments)) {
            if (match.Success) {
                string s = match.Value.Trim();
                if (match.Groups[1].Success) {
                    if (allowEscapedDoubleQuotes) {
                        s = match.Groups[1].Value.Replace("\\\"", "\"");
                    }
                    else {
                        s = match.Groups[1].Value;
                    }
                }
                else {
                    s = match.Groups[0].Value.Trim();
                }
                args.Add(s);
            }
        }

        if (removeFirst) {
            args.RemoveAt(0);
        }
        return args;
    }
}