Go and Chess would be good candidates for games with a very high branching factor (bot resistant) and you have the advantage that people are already familiar with them.
Oh hell no! Those are two of the least bot-resistant games ever! And the most simplest way to use a bot here is to simply start one of the 1000 free KI-programs, set it so the highest difficutly level and play every move of your opponent in that game and insert your KI's move to the site. (Remember, the world's BEST chess player bairly got a draw against the best chess computer..and people playing on those kind of sites probably will be below his skill level)
So if anyone knows any site that's offering chess or go for bitcoins...please tell me ;P
That will be the MOST DIFFICULT task to create a game where noone can use a bot/program/tool to get an advantage. At sites like gameduell.com they have many employees just working their heads around this one single issue.
I've been working in the games-industry and you wouldn't believe the tools that are out there just for simple games where noone can win any money. Imagine what people are doing if there is money in the game.
The key here(or at least that's how the big players are doing it) is to make the detection of cheaters as good as possible.
But even if you detect a cheater, then there is the issue: What to do with that person? If you ban their account they can simply create a new one! With the bigger sites they have to verify their accounts through a bank account or credit card or even passport.
If you have answers to those questions, go get 'em!
I think the idea can work, I've been looking at this before, but I got scared of by those issues.
I'd also consider teaming up on a project like this(however I do not have answers to those questions
- I'd know how to cheat though
), if you are interested in just some initial talking you can PM me.