I had some ideas of what they could do if they made a season six, so I will now share them with the iNterweb.
-An hour long episode that ends the shipping war and gives closure for both ships.
-A driving episode where Carly wants to get her license but her, Sam, Freddie and Spencer get stranded on their way to the DMV and by the time they get there, it's closed.
-A special where Carly returns from Italy to find out that everyone has changed (e.g. Sam being the popular cheerleader, Freddie being the jock, Gibby being the nerd, etc.) and has moved on from iCarly.
-A crossover special where Socko and Cat's brother are revealed.
-An episode where Carly and Gibby get trapped in an elevator and... they kiss at the end.
-An episode where Sam and Melanie switch places.
-A special that shows an actual iCarly webcast for a half-an-hour (e.g. make it like we're watching the webshow without all the not webshow stuff. Just like it's an actual webcast)
-A special/movie where Sam tries to escape from Malaysia (as a prequel set after iToe Fat Cakes)
-And, finally, they could do a whole re-tool/re-format season/spinoff that has Carly join an acting troupe at her boarding school in Italy. The troupe/club would be named in honor of iCarly and Carly would be treated like a celebrity/legend. The rest of the gang's exploits in Seattle would be shown as subplots. (BTW, the "i" in iCarly could then stand for Italy or the acting troupe.)
That's all! It would be cool if they actually did any of these!
Peace out suckaz,