OK. My bud's bringing over the Big G on Friday, June 10th. He's gonna be 1,800 points. So here's my team...

Ares (Unique): 275 points
Batman (Unique): 188 points
Flash (Unique): 150 points
Green Lantern (Unique): 225 points
Hawkman (Unique): 115 points
Red Robin (Unique): 90 points
Shazam! (Unique): 256 points
Superman (Unique): 265 points
Wonder Woman (Unique): 198 points

Damage Shield (x4) 40 points

TOTAL POINT VALUE 1,802 points

My question is should I drop the Damage Shield I'll be attaching to the Flash, Shazam!, Superman, and Wonder Woman and pick up the JLA's Atom?

I'd say there's a good chance that Galactus will completely destroy this team, particularly his 1800-point version. You just won't be able to beat him down fast enough. As soon as he hits Pulse Wave, it's all over. Damage Shield in particular will do absolutely no good against Galactus, because:
1) It requires him to make a close-combat attack against you to trigger it, and there is no reason Galactus would ever need to make a close combat attack against anyone but Red Robin on this team.
2) He always has at least Toughness, so that would absorb any Damage Shield damage.

You'd probably last a little longer if you used those points to put ICWO on your heaviest-hitters. Without Armor Piercing, Flash serves virtually no purpose on this team, and Batman even less.

Hate to say it, but this team doesn't stand much of a chance against Galactus unless your buddy is mentally challenged. Check azs' article on beating Galactus to see what sort of team actually has a decent chance of beating him. This one will let you lay out a massive amount of damage to start, but if you get him to his last dial I'd be extremely surprised.

honestly i think the best team would be all the Ultimates members, all the KC members and all the Mystics peices against an 1800 pt Galactus no matter how much more that team is

but even then i think Big G will win. heck i think he might even with at 1200 against that team

Don't play that team. You will get destroyed. You might have a shot with that team if you can convince your opponent to use a weaker version of Galactus. As it stands, he will stomp your team and neither of you will have fun. In fact, the best thing you can do for fun is for both of you to build 1,800 point teams and try to take out Galactus using the Scenario rules.

If you still want to try to defeat your pal with the 1,800 Galactus, you need a lot of stealth, Mystics and wildcards. Azs' strategy guide outlines it perfectly.

Ok, I understand using KC as they are for the most part insanely powerful...but Batman appears to be a waste in this, at least when I use him, I use him for Incap. and against the Big Man that's useless...and his defense is pitiful....unless you park him next to WW....I think you'd have some problems....but hey I could be wrong...I've never toppled the big man myself.