As if you didn't already get enough playtime out of your PC version of Portal 2, Thinking With Portals has compiled a "must-have" list of 25 community created co-op levels. These were painstakingly built as entries to the Summer Mapping Initiative, and are sorted on the TWP forum in order of community rating.
Installing user-created maps is a simple affair, and - if Rock, Paper, Shotgun's rundown is anything to go by - completely worthwhile. If you missed last week's awesome Steam price for Portal 2, you can still justify a fresh purchase with these new, free maps. If you already have Portal 2...then you can thank us with offerings of livestock and liquidated retirement funds later. Go get your free maps!
Here's the list, in case you're still on the fence:
Grand Prize Winners
[SP] Patent Pending by ebola
[SP] Infinifling by MrTwoVideoCards
[SP] Edifice by Omnicoder
[SP] Sphere: Delta Bunsen! by Lobster
[SP] Cubes 'n' Funnels by Will T.
[Coop] Redirecting Redirection by MrTwoVideoCards
[Coop] Fast Bridge by Skotty
[SP] Chamber Six by Nezzy
[SP] Discouragement Encouragement by Groxkiller585
[SP] Don't Eat the Paint by CaretCaret
[Coop] Fling Bridge by Kosire
[SP] Variation Susceptibility Test (VST) by no00dylan
[SP] Speed Gel Is Fun by supersandvich
[SP] Cubi by AmnDragon
[Coop] Mp_coop_Versus by Pete
[SP] Lost in Testing by KenJeKenny!?
[Coop] Abandoned Chamber by Hunter-Killer
[SP] Missing Geodome by Kay
[SP] Wall Button and Box Racing by lilBro
[SP] Overgrowth by slowdevelopment
[SP] Motanum's Main Four by Motanum
[SP] Rainbow's Competition Entry by Rainbow
[SP] PMK 6 by mazk1985
[SP] One in the Chamber by KrispyTheKorn
[SP] Laser Funnel by Nicky397