Wow, what a question. What I would most like to fly (that I haven't already)?
In the following order.....
My own machine!
then (with appropriate ordnance included of course....
):
Rooivalk the ultimate gunship
AH-1Z Cobra the latest cockpit systems and I've always wanted to fly a Cobra. The AH-1J or T if the Z is not available!
A129 Mongoose agile and sexy are it's middle names
Bell 214 ST they just dont make them like this anymore
Bell 230 they just dont make them anymore and they look great
MD 902 Unique. and they may not make them much longer
KA-50 Russian attack power: love to sample it
S 92 A Black Hawk that you can walk around the back in, fantastic!
the A-10! I know its not a helicopter - but it's so good it could be squeezed into anyone's wish list!
....but really I'll fly anything that is free and looks safe!!