I get rid of the slipcovers. Symmetry problem solved, because they're all naked!
No, really, I think they're tacky, with the UPC hole on the back. And the slipcovers have the exact same art and layout as the actual case. Off they go.
It was awesome when they did have UPCs on them, then you could (if so inclined) swap a cheap crappy movie with a more expensive good one, and 99 times out of 100 the clerk would never notice the switch, until the pissed off person who bought the crappy movie with the good slip cover came back to the store to return it. This actually happened to me once; I bought Chronicles of Riddick (mainly because it was a 2 for $20, I really wanted Eternal Sunshine of the Spotless Mind, and Riddick was the most attractive of the other choices) only to get home and discover I got Ray inside the slip cover. I did not return it.