Default settings should be just fine buddy. What exactly isn't working? Give us your computer specs and tell us what plugins you're using. I may not be able to give you the "ideal" settings, short of telling you to NOT bugger with the default, but maybe someone else can.
Simply saying "What's the best settings?" on a game won't give you much help.
Also note that a few of the mini-games haven't been tested on the Mario Partys and might not work well. Check the FAQ, it'll give you some help too.