C#

First time here! Feedback very welcome! Still reasonably new to C#/OOP - don't feel fully confident in it yet.

class ToDo
{
    private List<string> ToDoList;
    private string message;

    public ToDo(){
        ToDoList = new List<string> ();
    }

    public string Message {
        get { return this.message; }
        set { this.message = value; } 
    }

    public string AddItem(string item) {
        ToDoList.Add (item);
        return item;
    }

    public string RemoveItem(string rItem) {
        for (int i = 0; i < ToDoList.Count; i++) {
            if (rItem == ToDoList [i]) {
                ToDoList.RemoveAt (i);
                Console.WriteLine ();
                Console.WriteLine ("Success.");
            } else {
                Console.WriteLine ();
                Console.WriteLine ("Failed - No record found.");
            }
        }
        return rItem;
    }

    public void ShowList(){
        foreach (var listElement in ToDoList){
            Console.WriteLine (listElement);
        }
    }

    public static void Main (string[] args) {

        ToDo toDo = new ToDo ();
        bool loopFlag = false;

        while (loopFlag == false) {
            Console.WriteLine ();
            Console.WriteLine ("Main Menu - Pick a Number: \n ");
            Console.WriteLine ("1. Add Item");
            Console.WriteLine ("2. Remove Item");
            Console.WriteLine ("3. List All Items");
            Console.WriteLine ("4. Exit \n ");

            try 
            {
            string userStringResponse = Console.ReadLine ();
            int userIntResponse = Convert.ToInt32 (userStringResponse);

            switch (userIntResponse) {
            case 1:
                Console.WriteLine ();
                Console.WriteLine ("You chose Add Item - Please type the item to add: \n ");
                string uAddResp = Console.ReadLine ();
                if (uAddResp == "") {
                    Console.WriteLine("Please Enter Valid Data - Field cannot be blank.");
                } else {
                    toDo.AddItem (uAddResp.ToUpper());
                }
                break;
            case 2:
                Console.WriteLine ();
                    Console.WriteLine ("You chose Remove Item - Please type the item to Remove: \n ");
                string uRemResp = Console.ReadLine ();
                toDo.RemoveItem (uRemResp.ToUpper());
                break;
            case 3: 
                Console.WriteLine ();
                if (toDo.ToDoList.Count == 0) {
                    Console.WriteLine ("No record found - List empty.");
                } else {
                    Console.WriteLine ("Current List: \n\n");
                    toDo.ShowList ();
                }
                break;
            case 4:
                Console.WriteLine (); 
                Console.WriteLine ("You chose Exit - Press any key to exit program.");
                Console.ReadLine ();
                loopFlag = true;
                break;
                }
            }   
            catch (FormatException fEx) {
                toDo.Message = fEx.ToString();
                Console.WriteLine ("Error: Incorrect Format (Please type a single number from the Main Menu) \n\n" 
                    + toDo.Message);
            }
            catch (Exception gEx) {
                toDo.Message = gEx.ToString();
                Console.WriteLine ("Error: " +
                    "\n\n" + toDo.Message);
            }
        }
    }
}