I always fly Delta after having debacles with Airtran and American. A bit more pricey but they get me there on time, pretty much always. Oh and I've got status and blah blah so that is nice. I've also heard great things about Southwest as well and SW is adding more and more flights from ATL. I know recently they did open up LAX and Vegas nonstop for cheap.
Bite the bullet and fly out of ATL. Since its a big airport, most of the time you can get a direct flight. Don't be a cheap @$$ and get a flight with 5 connections. You'll kill yourself after the 2nd layover. In fact, just about any layover longer than 45 minutes sucks. A 45 minute layover is perfect. You pretty much just walk to the next gate.
Also look at flying into either LAX or Las Vegas. Driving across LA isn't that bad during the middle of the day so when you arrive at 11am or whatever, just go out, get your car and then you can scoot. In the past I'd land at LAX and then drive over to San Bernardino. I could leave LAX and get over there in about an hour and a half. Its not that bad (especially in a Mercedes C class or Challenger) and quicker than waiting 2 hours for a puddle jumper to take you over there. Driving in Vegas is easy as long as you don't go down the strip.
If you check a bag, LAX and Vegas are SUPER slow. Be prepared for that. Typically I go and grab something to eat then go get the bags as it will take 20~45 minutes. However ATL is super quick. If I get in at gate C, D, E, or F, by the time I get to baggage claim, my bag is already there. If I'm closer, I gotta wait 5 minutes.
Oh and don't fly into John Wayne. Its more expensive and a cluster. Both LAX and Vegas have the capacity to deal with larger crowds. Oh and if you do fly into LAX or Vegas, legit give yourself 2 hours from time of arrival to departure. I've gotten stuck at both during a random peak hour and it sucks.
I will say one benefit of the bigger airports is getting a decent rental car. They have the inventory. I've gotten screwed at a smaller airport with a crappy car with 50k on it and half the paint missing. That sucks. Having big inventory, if the car is crap, you can reject it instead of being screwed.
If you fly into Ontario, prepare to get some crappy connections and it be expensive as crap.
If you do come down to ATL, do off site parking at Peachy Airport. This does a few things: First off, look for a groupon and you can get cheap covered parking. Their shuttles are quick and get you there in no time. Also you avoid the cluster that the ATL airport is right now...and for the next bit. You are far out so the shuttle driver deals with it instead of you. It is a bit of a pain coming back but you've got time so deal with it. Its just nice coming back and NOT finding hail damage on your car.
Oh and DO NOT plan any stops around the ATL airport. Its a bad time down there.
Lastly, take the 5 seconds beforehand and look up a map of how the airport you are flying out of/landing in is arranged. I friggen hate it when people can't understand the ATL airport. Its SUPER SIMPLE. However people would prefer to walk 500 miles instead of getting on this awesome train that takes you where you need to go...super fast.
That is all I gots for right now.