Funnest map setting was one of two things, one on Chasm or some map like that, Pistold, crossbows and sniper rifles, thats it, and make it elimination with 5 lives and one shot kills, lots of fun to be had.
Another good one is to make a map with lots of twist and turns and hidey holes, have one person proxy mine the eff out of the place, up to 30, i think thats when they game started to reset the mines, then make another player go through it, lots more fun to be had, unlimited ammo made it alot easier.
I already singend that petition ages ago, i was number 4007