What Do You Play at Cons?

When you go to a con, do you lean toward playing games you already know and like? Or do you prefer to play new games you've never tried?

I'm thinking – just thinking, mind you – of running something at Con on the Cob in Richfield, OH next fall. Part of what I'm considering is which rule set to use. I figured running something with a high level of popularity would be more likely to draw participants. So I made a list of all the rule sets out there that I'm currently in love with, and tried to see which ones other people were in love with too by looking at how many members are in the Google communities for these games. In short, where do my preferences overlap with those of other people? Here's what I got:

Not sure this is really a valid way of picking a game to run, but I suppose it's as good as any other.

So back to my original question. When you go to a con, do you lean toward playing games you know and like? Or do you prefer to play new games you've never tried?