Juggernaut: each side starts with a juggernaut(a uber strong vehicle) which serves as a spawnpoint, the goal of the mode is to destroy the other teams juggeraut. Think of this in tight urban maps.
*thinks Titan from BF2142* actually I hate the Battle Field games but that mode was actually fun on BF2142
brilliant gamemode that! Also this reminds me of a game called goliath. You had to stop this huge tank thing from destroying your stuff. It was great. Infact if anyone wants a game (you can download it free from http://www.goliathgame.com/download.html and its online) I'll come along
I've done that in garrysmod, and it is sweet. Would crash most other people's comps though. When I first tested out my new system in Gmod, I couldn't believe my eyes. 50+ enemies at once without a hint of lag with a rotating cannon killing them all one by one.