This is a tough one to pick one, for overall playability I would vote the first gen Srixon u45, playable off the deck for sure. they messed up the u65 by making it too round.
Pure driving iron, the callaway X utility was ahead of its time, but currently for my home course which is always 15-25mph, its OG p790 UDI.
Great commentary thanks to the Mayor hahaha.
I love the driving iron because it can make you look like a pro when ball striking is good, and conversely like a pure hack when you are just a bit off.
(We'll have native video uploading ready soon, but youtube for now)