Iron Man #118- what can I say about this one? Tony Stark gets thrown out of the SHIELD helicarrier and has to try and don his armor before he falls to his doom. Something about rogue SHIELD agents and all that... this was from the creative team of David Michelinie and Bob Layton, who first depicted Tony Stark as an alcoholic. That would continue in later stories and even in the movies- for that and just the sheer fun of these stories I think Michelinie/ Layton have to be considered the definitive writer/ artist team.
Oh, and this is from the time when Iron Man carried his armor around in his briefcase!