Well, it's not really important in the grand scheme of things, of course, but I'd personally love to see ROH make Dave Meltzer eat ten grand. I understand and respect that Meltzer is a big voice among wrestling journalists, especially in the minds of fans who prefer indie or Japanese style wrestling, but he's such a gigantic mark for himself that he should be taken down a few pegs.
Chicago and London have especially hot crowds and if Cody and the rest of the Bullet Club who're primarily working ROH get the word out, if they really get out and let fans know about the bet, then I think they could have a realistic shot.
As to who I think will come out on top, my heart would prefer ROH to come out on top but my head says that it'll be Meltzer. Ring of Honor has pretty much prided itself for the last 12 years or so as basically being King of the Indies and their crowds pretty much reflect that. I came across a report just a little while ago revealing ROH's total attendance for the first half of this year, the show average, etc. For the first half of this year, the report claims Ring of Honor drew a total of 24,307 fans with an average show attendance of 1,105 fans. The most attended event in ROH history took place during their Supercard of Honor event this year during WrestleMania weekend, which drew 3,500 fans. So basically, Meltzer's bet would require ROH to almost triple the biggest attendance they've ever had. You'd also think that New York would be a final candidate considering it's ROH's biggest market.