Give me Johnny.
Iggy was frustrating at times and never brought us a championship though coming close in '04. He had a decade of being a top 10 winger, and 4 or 5 years as one the game's most dominant power forwards (unfortunately he was up against HOFers Peter Forsberg, Brendan Shanahan, Vincent Lecavier and Joe Thornton for a number of those). Iggy also potted a TON of empty net goals throughout his whole career. And finally, he was a shell of himself IMO for the last 2 or 3 years of his time in Calgary.
I know the book isn't written on Johnny, but IMO he is slightly more skilled (better skater, better hands, equal game sense; Iggy with the edge in shot and physicality), and there's a chance we could contend with him as our superstar for a number of years to come (if this isn't a sick anomaly of a stretch we're in lol).