TTYD > TOK > 64 > Super
TTYD is good, sucks about all the padding, but it's still clearly the best PM game. Only one to consistently have characters and battle mechanics worth actually getting invested in.
TOK is also generally good, it's aesthetically beautiful and has a fantastic soundtrack. I think the battle system is generally interesting but I ended up paying off the Toads to skip a lot of random encounters later on. It gets just tedious after a while, which to be fair is a common JRPG problem and affects the other PM games as well, but it's more of a problem in this game because the random encounters take actual effort to wipe out quickly. The boss fights are great though and are mechanically my favorite in the series. The partners outside of Bobby (who is great) are disappointing and the lack of original characters is also greatly disappointing.
64 is decent but it's too simple for its own good. The story and premise are too vanilla compared to both TTYD and SMRPG. The SMRPG comparison in particular really hurts this game for me because it's a downgrade in basically every way. The music isn't nearly as good, the settings aren't nearly as interesting, the partner characters are mostly uninteresting and basically stop existing narratively after they join the party, the battle system is even simpler and also way too easily broken by just spamming the Star Spirit abilities. Like I get Mario RPGs are meant to be simpler and I even appreciate it because SMRPG itself was the game that originally turned me into a lifelong JRPG fan back when I first rented it at 5 years old. But PM64 just takes it too far IMO. SMRPG and TTYD are simple games but they are able to hold my attention even now, but PM64 is a bit of a bore for me. I don't want it to come off like I hate this game or anything though, I still think it's fine, it's just not a favorite of mine.
Super is not good, a few of the early chapters are decent but after the Mimi and Francis chapters are over the game basically completely runs out of gas. I really hope the reactionary movement up pretending this game is some misunderstood masterpiece is over now. I don't care how bad Sticker Star apparently was, Super just ain't it.
I didn't play SS or CS, I guess CS I would maybe be interested in trying out some day but I don't see much of a point in playing SS when basically nothing about the game sounds appealing