Originally posted by fryke
Don't laugh at him. Take him seriously. Ask him (carefully) about (small) problems he's having with the PC. And don't blurt out "Doesn't happen on a Mac!", rather just nod, say you understand that this sucks sometimes and then tell a small story about something that _doesn't_ suck on the Mac. Humbly. That's the way to convert them.
I often fall into the trap of bragging myself when talking to PC users that are whining. ("My PC did THAT again..." - "Yes, I know it was like that in the computer world before UNIX came around. You know, even the Mac is UNIX now. Basically, Windows is the only OS left in the 20th century technology, if you dare call it technology at all.")
Just give them the feeling that you have less problems and struggles since you switched to the Mac. They'll believe you, if you also admit that there ARE issues:
"Yes, the Mac _is_ currently stuck at about one GHz. And it's a drag. However, I've found out that all the GHz talk I've been into myself only left me with _less_ money at the end of the day, because it urged me to _always_ keep up to date with my CPU and graphics board, instead of actually _achieving_ things with my computer."