Check for the latest host list received by using MasterServer.RequestHostList.

You can clear the current host list with MasterServer.ClearHostList. That way you can be sure that the list returned by is up to date.

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

public class Example(MonoBehaviour):

	def Awake() as void:
		MasterServer.ClearHostList()
		MasterServer.RequestHostList('LarusTest')

	def Update() as void:
		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()