Obviously, ATLiens is the better album of the two, the one that is considered a true classic in the sense that it will go down in Hip-Hop history books as such. Tha Dogg Pound's debut is a classic, but not in the definitive sense; it's more like a classic in retrospect. I will say that I've listened to Dogg Food more than ATLiens, let alone any OutKast album in general.
So if I were told between these two, to pick one album to play all day, it'd be Dogg Food

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