Lot's of amazing arcade ports, that often offer some neat exclusive features.  For games that came out on multiple systems, the X68's versions were the best 95% of the time.  Also being an extremely popular machine for doujin makers, there are a lot more exclusive games then most people realize.  The X68 was a machine with no rules really, people did some crazy stuff.  As geise mentioned, if you check out my channel there is a lot to see.