Hands down, Carter's Lake with Louie Bartenfield. Magnum spots and if they're biting, some big Stripers and hybrids. Not to mention the occasional walleye. Scenery can't be beat and the boat traffic is usually really small, even in summer. Been on 7 trips with him, including this past Sat. where we caught alot of stripers and spots. Also, Rick Shoupe from Fish Allatoona, this guy can fish any area lake and get bit. Both guides I would highly recommend.
If you're going to hit Lanier, Trent Gober is really good. He will do it all. Rig it up, hook fish and let you reel them all the way to just driving the boat and you do everything else.
He's a good guide and has a great boat. I highly recommend him if you're going to Lanier.