I was excited for Winter Bash this year, and it started off pretty fun. However, it became apparent within a few days that some fellow English Language & Usage users (including moderators) weren't exactly playing fairly. I think this is obvious to everyone by now but if not just take a look at http://meta.english.stackexchange.com/ and you'll immediately see 2 posts solely for gaming the meta-specific hats. There's also been examples of bounty-trading, deliberately creating questions to award Marauder hats, coordinating votes in chat, and maybe other things I'm not aware of.
To put it frankly, this made me really quickly not enjoy Winter Bash 2013 much at all, and I've come close to clicking "I hate hats". I thought this was supposed to be about helping out the sites we enjoy, but they've basically taken that out of the equation entirely. Most of what's going on there won't help the site in the long run, and some of it might even damage the site (if only slightly). Now, when I look at the leaderboards, I can't tell who is serious and who is cheating, and I've basically lost all motivation to try to get any more hats. It seems to me now that the way to get the most hats involves harming the site in some of the above ways, which is not something I'm going to do.
It would be good if stricter policing was enforced against cheaters. Maybe none of these people deserve suspensions for what they did, but at least the hats they unfairly got should be taken away. It would be hard to enforce all the rules network-wide, but at least the very blatant cases should be penalized. That would make it more fun for those of us who want to get hats fairly.
Along the same lines, hats like "Oh the Horror" were probably a bad idea to start with. Meta guru badges are normally basically impossible anywhere other than here. Few meta sites other than this one even have 40 regular voters. In my opinion hats should be equally obtainable on all sites, or at least as close to that as possible. I suspect that these sorts of practically impossible goals are a lot of what is causing people to cheat. Some people would cheat anyway, but if the hat required an answer with 15 upvotes rather than 40 I think most would try to get it fairly (and maybe moderators would be more willing to punish cheaters). If you want to make a hat like "Oh the Horror" that's effectively specific to one site, go all-out and make it actually specific to that site. Putting more thought into what sort of beneficial effect the hat is supposed to have on the site and making sure it has the desired effect even for smaller communities would really make a big difference in my opinion.