I don't think you can swim because of your shoulder, you can't kick or water run because of the PCL.

I do really like the idea of on legged drills on the bike or even going to the gym to do exercises on the other side only. I know it sounds crazy but there is good research to show that exercising the non-injured side during recovery helps to slow the muscle loss on the injured side.

I'd also look into Pilates. You should be able to do a lot of the mat workouts with your brace on.

Maybe a virtual reality car racing game will get the adrenaline going?