MasterServer.ClearHostList  

function Awake() {
    // Make sure list is empty and request a new list
    MasterServer.ClearHostList();
    MasterServer.RequestHostList("MyUniqueGameType");
}

function Update() {
    // If any hosts were received, display game name, the clear host list again
    if (MasterServer.PollHostList().Length != 0) {
        var hostData : HostData[] = MasterServer.PollHostList();
        for (var i : int = 0; i < hostData.Length; i++)
            Debug.Log("Game name: " + hostData[i].gameName);
        MasterServer.ClearHostList();
    }
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    void Awake() {
        MasterServer.ClearHostList();
        MasterServer.RequestHostList("MyUniqueGameType");
    }
    void Update() {
        if (MasterServer.PollHostList().Length != 0) {
            HostData[] hostData = MasterServer.PollHostList();
            int i = 0;
            while (i < hostData.Length) {
                Debug.Log("Game name: " + hostData[i].gameName);
                i++;
            }
            MasterServer.ClearHostList();
        }
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    def Awake():
        MasterServer.ClearHostList()
        MasterServer.RequestHostList('MyUniqueGameType')

    def Update():
        if MasterServer.PollHostList().Length != 0:
            hostData as (HostData) = MasterServer.PollHostList()
            i as int = 0
            while i < hostData.Length:
                Debug.Log(('Game name: ' + hostData[i].gameName))
                i++
            MasterServer.ClearHostList()