I don't know if it's the advanced graphics, the rich gameplay, or the XBox Live support but for some reason hot girls LOVE Halo 2. They just love it.
"Have you ever wondered if that pink Master Chief might really be some hot girl playing in her underwear?"
"What is better than a hot chick? A hot chick in her underwear? What's better than that? A hot chick in her underwear playing HALO."