If you play Mario Tennis on the Donkey Kong jungle court and make a point to never let the ball hit the ground (just lob all the time), you've basically got Mario Volleyball.
I like the Mario sports games, they simplify it to the point that I'd actually want to play the sports. But then I later learned that Mario Golf is just Hot Shots Golf with a makeover (which I'm okay with, I mean, solid simplified golf foundation there).
Super Mario Kart - Great courses, great presentation... but I just can't get that powerslide down.
Mario Kart 64 - Forgetting that I couldn't turn worth a darn in SMK, I tried this game... and wow. Powersliding is a lot easier here, turning feels more responsive - this is what I WANT Mario Kart games to control like. Everything since just feels more like Super Mario Kart (I tried Mario Kart Double Dash, it's just not the same). As a result, I liked this Mario Kart game... and I used to be so good at it that I thought the CPU players were an absolute joke - until I stopped playing it for years and found myself getting whooped by Toad.
Mario Golf - This used to be my favorite, man. I'd be in the house for hours on end, trying to Get Characters and getting a birdie on every hole (the Ask Dan guy said on that Jet Force Gemini / Donkey Kong 64 video that a birdie on every hole would unlock something special), pulling my hair out on trying to clear Ring Shot mode... good times. Great music too. And I used to be so good at it that putts were never a problem. Loved it, couldn't find any faults with it. That is... until that one fateful day when the game froze up and decided to delete ALL my saved data. That's the only time I felt that game saves would have been better if they were saved to the memory card. After that, I didn't have the will to spend another 40+ hours to unlock everything again. Imagine if a saved-game-deleting freeze happened when I was playing Zelda: Ocarina of Time.
Mario Tennis - The most accessible Mario sport I think, very fast, lots of fun, and the roster's bigger (Paratroopa!!). I managed to beat all six cups with... either Yoshi or Paratroopa, I forget. My favorite moment in the game was when I was playing against Baby Mario, he was too good, I was on the ropes. I hit the ball straight towards Baby Mario, I'm thinking "Oh no, he's going to slam it past me, I just know it". Baby Mario winds up for the slam... but the ball hops over his head, Baby Mario goes "WAGH!", and I score a point. One of the funniest things I've ever seen.
Mario Golf Toadstool Tour - I don't know, didn't like this one as much. I know it's basically the same game, but I kind of miss the music and courses from the original game. I did like that Koopa Troopa's always on the verge of falling over whenever he takes a swing, though.
...and I haven't played any other Mario sports games. I was kind of disappointed to hear that the previous Mario baseball game (just the fact that there was a Mario baseball game boggles my mind) gave you no control over fielding, but in hindsight, virtual baseball games bore me to death. I tried playing a few baseball games, thinking there'd be something to hook me in... and there never was. The only baseball game I ever enjoyed was one of those Ken Griffey Jr. games. I think it was Ken Griffey Jr.'s Winning Run for SNES. I liked when the umpire would tap the screen if you didn't do anything for a while.