I have created a Gears of War 2 COG Tags and Collectibles Achievement Guide in HD. With this guide you will gain the following achievements: Collector (5G), Pack Rat (15G) and the Completionist (30G).
Watch them all at my YouTube along with other achievement videos I have created for other games. http://youtube.com/user/steve0384
Watch: ACT 1, ACT 2, ACT 3, ACT 4 and ACT 5.