These lists are based on global unique users connected to Xbox Live. Major Nelson had no access to the Arcade title data this week, so no Arcade list for now. Here are the top 5 for both charts, see the source for the complete top 10 list.
Xbox 360 Top Live Titles
1. Halo 3
2. Gears of War
3. Madden NFL 08
4. Virtua Fighter 5 Demo
5. Guitar Hero II
Original Xbox Top Live Games
1. Halo 2
2. Battlefield 2: MC
3. Counter-Strike
4. Star Wars: Battlefront 2
5. Madden NFL 08
