The most imaginative interior of a helicopter had to be the A 109 in Jurassic Pork (or was it Juristic Perk?). The exterior shot was a regular 109, but inside it was like a 747. Room for hips and actually some room for legs and knees. It looked about 10 feet wide and 6 feet high.
I want one like that - compact outside, not so squeezy inside.