Met Mario once when I was volunteering at his golf tournament. He was INCREDIBLY friendly, and made it a point to meet all of the volunteers and take pictures. He asked me if I played hockey - I'm 6'5" and a good two bills - and after I told him I was studying CS at CMU, he told me that I should help out with the Pens website, because no one at the league liked it. That doesn't sound all that funny, but man, the delivery on it was great.
Can't say enough great things about how friendly he was with everyone, even like, the lowest volunteers. Basically, I can confirm to you what everyone knows: Mario is perfect. As far as intentionally trying to meet him, I think I'd err on the side of caution; Mario is private and while I'm sure he's respectful to a fault, the more aggressive fans get with hounding him, the less likely it is for any of us to see him out and about.
I also randomly saw MAF (and Veronique) at the baggage claim at the airport. I hate to be that fan, so I just said hello en francais and he smiled, said hello back. If you think his smile is big and white on TV, wait until you see it in person.