Which types of gambling cause the most problem gambling?

All of them. Any form of gambling can be problematic depending on how much of a "gambler" you are; and the depths of your pockets. My advise is to avoid these activities all together...It ends up being a lot cheaper in the long run.
ANY. Any gambling can cause a problem due to variable reinforcement . This means you never know when you may win and you keep chasing that. Once in a while you win but never enough to be ahead.