Interesting topic! ;D
Now let's see what I have in my library....
I'll start with Persona 1 and 2:
I like 'em mostly because of how weird they are.
They have a great color palette and great contrast that makes them really eyecatching.
But what really sells me on these is the strong imagery and the symbolism.
(https://vignette.wikia.nocookie.net/megamitensei/images/d/de/Coverforpersona.jpg/revision/latest?cb=20130826030757)
(https://vignette.wikia.nocookie.net/megamitensei/images/2/22/Innocentsincover.jpg/revision/latest?cb=20080608220940)
If I have to choose between the 2, Persona 2 wins. Mostly because the box art of the first game is a little bit cluttered compared to the second game.
...and since I don't want to that guy that only talks about one series:
(http://static.giantbomb.com/uploads/original/0/30/647340-fable.jpg)
Say what you want about Peter Molyneux, but the first Fable was a great game... Even if it was over-hyped.
I like how the box art tells you everything about the game with the protagonist watching a reflection of his future, of what you can become.
(https://vignette.wikia.nocookie.net/metalslug/images/4/4e/Box-art-metal-slug-xx.jpg/revision/latest?cb=20100121130809)
This one is simple, it's just a really badass box art.
It's cluttered AF but I love it anyway. XD
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@MasterXtreme
GTA box arts are some of the most iconic around. Good choice!
@System423
Oh, I like the FE one! :O