I cant think of many places that are good for a fight, I'm using the companion glitch so I've got 6 followers, so places like Fortification Hill and the Deathclaw Promontory are a push over.

Where do you go for a good fight?

Hidden Valley Bunker, but if you've done the promontory then :shrug:
The Boomers, gather them all up then attack

I hadnt thought of killing all the boomers, theres plenty of blood to spill there.

Lots of leather for the Vault 21 girl, Sarah Weintraub, and lots of explosives for your players, Win, WIN!
Use a melee weapon with them though since they are very spread out and it'll make it a level fight

if you do not mind pissing off fraction

brother hood of steal bunker

camp mc carren
new vegas strip

Well the fort is the place i'd imagine you'd get the biggest fight, next to that i'd say hidden vally or camp mccarren if 1st recon is still there. Quarry Junction's always a challenage on higher difficulties, as is NCR Correctional Facility, but youd roll over it with 6 companions.

You could always save > go ahead and start the battle at the dam for who ever and just take on everybody.

Edit: I did mean to say to try these on increasingly higher difficulties or on hardcoe mode.

Just went and killed everyone at Hidden Valley, I just punched a Paladin and watched, everyone but Raul died. Pretty good.

Jacobstown, all those super mutants should put up a fight

Hidden Valley is easily the toughest fight, I think, the Fort's got a lot of guys but many of them have crap weaponry and it's open enough for companions to mow down Praetorians before they can close.

The Brotherhood has a ton of high-powered (well, as much as they can be in NV) energy weapons and those incredibly durable turrets to back them up; and you have nowhere to run.

The entire Mojave. Factions be damned.