My favorite game in the series was Super Mario 3. I first played it on the SNES when it was part of the Super Mario All Stars cartridge. I really liked the levels, especially the variety of landscapes and the secrets you could find if you had the right powerup.
Super Mario World is just as good imo. Everything I liked about 3 and more, plus the star road levels, that was a good game.
The most recent game I loved was Yoshi's Wooly World on the WiiU. Excellent art style and super fun levels, especially the unlockable bonus levels.
Oh and let's not forget Legend of the Seven Stars. That was a fun and bizarre story.
That being said, does anyone else think the Mario universe is just fucking weird? How did the creators come up with Italian plumbers who can jump really high saving a Princess from an oversized turtle in a fantasy land with walking mushrooms? Who thought that was a good idea? What inspired them? I think the only reason it became popular was because Super Mario on the NES was one of the first decent games, and most players were kids who didn't care about the game's universe and narrative beyond saving the princess.
If Mario wasn't the first popular platformer in the 80s and was instead introduced today, nobody would take it seriously. Since we all grew up with Mario, it's a thing we accept as is. Of course high jumping Italian plumbers discovered the mushroom kingdom and rescued their princess from Bowser, again and again and again. Of course little dudes with mushroom heads are ruled by a blond haired human. Of course giant pipes are a normal mode of transit. Of course goombas and koopa troopas are the baddies.
Seriously, how did this universe come about?
That makes a lot of sense. Katamari Damacy is also an excellent game with such a bizarre story. I'm guess I'm a fan of absurdity.