Real life. I'm not joking, if you're starting to get bored of all the games you play then it might be better to shorten your time spent on playing video games and do something else, that way the games that seem boring to you may get a lot more interesting. Games are like songs, the more often you play them, the more boring they get.
As for any decent open world games, I don't think I know any besides what has been already listed.