Gene Kranz
Watching "When We Left Earth" on Discovery, awesome stuff. Anything about NASA -- well, at least how it isn't getting dorked by Congress and is actually doing good science. It always makes me proud that our country pays for what it does for NASA and gets what it does -- I think the exploration of space is pretty damn important.
But regardless, is there anyone cooler in NASA than Gene Kranz? I don't think so.