Never would have thought to compare these bands - Top doesn’t do it for me, but they seem like they’d be a fun straight-ahead rock band. The Allmans did more of a hybrid blues-jazz-country thing, and I’d rather listen to them.
But I might be biased, I’ve seen the Allmans about 45 times. 
One of the defining characteristics of Southern Rock is the extended slide guitar boogie in G. At which the Allmans excel.
C’mon…any band that produced “In Memory of Elizabeth Reed,” “Whipping Post,” “Mountain Jam,” “Jessica,” “Blue Sky,” “Hot 'Lanta,” etc. is going to kick the ass of a band more known for its beards than its music.
Can I cast a write-in vote for Wet Willie?
I’d consider ZZ Top to be Southern rock. They did a lot of blues-based stuff, plus they got a shout-out in “The South’s Gonna Do It Again,” which surely rates automatic inclusion in the genre.
But yeah, the Allman Brothers are way better.
The Black Crowes
Even though I can’t name a single song of theirs (though I’m sure I’d know some if you told me) I’d have to say Allman Bros just based on how godawful ZZ Top is.
Pretty much the same here. And I do like ZZ Top. But they’re not a phenomenal band, just a decent, fun one.
Good lord, are you kidding? The Allman Brothers, of course!
ZZ Top are solid journeymen. The Allman Brothers are masters.
I’ll have to join the “you’re comparing apples and oranges” bunch. The latitude may be the same, but there’s a lot of difference in those longitudes.
Someone else mentioned adding Little Feat into the Allman, Skynard, Wet Willie, Marshall Tucker grouping - too bad they were from California.
Others that could be added into the Southern Rock genre
Atlanta Rhythm Section & Black Oak Arkansas
This is true, ergo question is moot.
They were a solid mid-level band, but the videos gave them top ten hits for the first time and made their faces nationally recognized, which just wasn’t true before that.
Nobody would even think to put their name into a thread title if it weren’t for the videos. Who would you possibly put up against the Allmans, even if only for name recognition? Maybe Lynyrd Skynyrd. But the rest of the southern rockers? Marshall Tucker Band? Black Oak Arkansas? The Outlaws? .38 Special? ZZ Top pre-MTV is in the same league. (Lower for me, since I’d much rather hear “Green Grass And High Tides.”)
They’re mentioned because of leggy women in short skirts first, the car second, and the music third. Maybe fourth behind the beards and guitars. That’s not a knock at them, but a tribute to their showmanship.
Elvis?
Sheeeeeit. Almost nobody. Duane’s chops alone would have run almost anybody short of Jimi Hendrix off the stage.
Well, in the same way some Southerners distinguish Texas from “the South,” I don’t really think of Top as being classic Southern Rock.
That said,
ABB had/has a much better grasp of melodies, and manages to inject some interesting modal breaks into lots of their songs. And they have the big sound coming from 2 guitars, keys, bass, 2 drummer. That’s really tough to beat.
Top had the great guitar tones. Billy Gibbons is a gearhead and guitar collector, and he’s always put a premium on tone.
I’d go with ABB by a large nose.
They’re a California band.
MTV ushered in the second coming of ZZ Top. They got pretty huge in the mid-70s, based on 1 or 2 songs that got airplay plus some solid early albums, eg Tres Hombres. Evidently their live shows were something to behold, but I really can’t stand the power trio format for live music (Joe Satriani being the exception).
I’m going to have to go against the grain and say I prefer ZZ Top.
You’ve said what I meant to. I’d add Barefoot Jerry but more out of personal tastes than for greatness. In fact the bands listed in the Charlie Daniels The South’s Gonna Do It (or whatever it’s called) all deserve a listen for nostalgia’s sake at least.
But the Brothers win the category, hands down. Especially the original group. After Duane and Berry, it a downslope run.
Southern Rock wasn’t big in Canada, and the Allman Brothers barely made an impression there. I never knew anyone who had any of their albums, so I’ve never been exposed to them beyond their few radio hits. “Whipping Post” is right up there with the best of any genre, though.
I like ZZ Top, right up to where Billy Gibbons discovered the sequencer. Then I lost interest. I will never forgive them for remixing their first six albums for CD with triggered drum samples and reverb that sounds like a tiled bathroom. Nonetheless, one of my favorite albums by anybody is “Deguello.” As a drummer who aspires to get better, I want to be Frank Beard when I grow up.
Allmans (starts sining Jessica riffs!)