When concerning these titles, I didn't really give a crap about critic scores; Mario Party I still found really enjoyable despite the slump in 9 onto 10. I adored Mario Sports Mix, its tournament mode is pretty great, I liked all of the sports it offered, and it had neat little Special Games, with Smash Skate being my favorite and Harmony Hustle being really fun to play with, though Bob-omb Dodge and Feed Petey aren't all too bad either. Sports Mix also has a great soundtrack, one of the most overlooked Mario soundtracks imo. Really the biggest issue I had with Mario Sports Mix was its rather dreadful character roster, being a step back from the DS game, Mario Hoops 3-on-3.
I really like Mario Super Sluggers too, for similar reasons for Mario Sports Mix. The Story Mode was pretty good, the Minigames were really fun, Graffiti Runner is easily the best one, and Baby Luigi is playable in that one.
Besides, they're all developed by different people anyway. Squeenix handled Sports Mix while Namco-Bandai handled Baseball and Next Level Games made Strikers Charged.