Here's a spoiler: there aren't going to be any surprises on the list I gave them.
I went with the idea of games that were accessible and fun and relatively easy to find. I also wanted to make it a fairly short list, to keep myself from getting out of hand.
Here's what I came up with:
Ticket to Ride
Take It Easy
Out of that lot, not knowing the folks involved, Take It Easy would be my top pick. I've had a lot of success with it with folks who have no interest in games to the point of getting repeat plays in the same sitting.
They went with Catan.
Which was my real introduction to designer games and I do think is a great game, as well as revolutionary one. However, I have also taught to non-gamers who found it too heavy. I love it but I have to wonder if it's too big a step from Trivial Pursuit.
If they had said Monopoly, though, my list would have started and ended with Catan :D
My takeaway from this is that I might be too conservative and too safe in my choices of games for non-gamers. After all, I know someone who used Puerto Rico as their game to break in new gamers. Although, they were dealing with folks asking for games. And I've seen folks who thought 7 Wonders would be the perfect introduction and that went up in flames.
I do sincerely think that people who play lots of games all the time often underestimate the complexity of games. (Teaching Race for the Galaxy with three expansions comes to mind. Seriously?)
At the same time, am I being too conservative? If folks have a regular game night with Trivial Pursuit, maybe they will want something longer and with more teeth. Maybe my bad luck with Catan just means I'm a bad teacher.
It is a good question. Yes, an overwhelming game can spoil someone from wanting to play another game but it isn't helpful if they aren't engaged or challenged.