The second map in the Halo 3 Legendary Map Pack is "Avalanche". This vehicle-heavy map is great for Big-Team objective game types like Capture the Flag and Bomb.
Control of the laser at the back end of the map is key and you'll need teamwork to get the flag back to your base.
Check out this Multi-Flag Battle Rifle CTF match where I didn't die. I also managed to snag two flag captures. Nice!