Here are the ones that I can think of off the top of my head:

SMK- Ghost Valley 2 (or the one with the feather short cut, might be a different one).

MK64- Wario Stadium. Great multiplayer for annoying friends with the lightnening bolt.

MKDD- DK Mountain. This was one of the few I did like from this game.

MKWii- Moo Moo Meadows. I thought most of the tracks on this version were terrible, but Meadows improved on Farm from 64.

MKSC- Rainbow Road. The best Rainbow road by far for me. I loved to use tailor made short cuts you could take using boosts and the bouncy track edges.

MKDS- Airship. great track design coupled with nostalgia, I couldn't believe that this wasn't on the Wii version. Loads of great tracks on the DS though.

Those are my favourites, at least according to my current ability to remember the tracks.

What are yours?

SMK- Ghost valley 2(just cuz of wii, haven't played original)
MK64- Bowser Castle(best one I can remember)
MKDD- DK mountain
MKDS- (never got it)
MKWii- Rainbow Road(best rainbow road!)

@Cowlauch- How do not like the MKWii tracks? I love all of them??

I think the tracks are absurdly wide on the Wii version. Also I think the design is bad with often little distinction between the actual track and the surrounding areas in terms of graphics. Overall I just found the tracks bland. If you want to know what I mean compare DS tracks on the Wii with the new ones.

MKDS- Waluigi Pinball, Airship (so many great tracks in this one, I couldn't pick just one! )

MKSC- The second Bowser Castle, I guess. I don't really remember any of the tracks from this one.

I never really take hardly any of that stuff into account.
As far as the tracks being bland, I found they were very creative, all the tracks were different, and they were fun to race on.
Why did you find the tracks bland?(besides graphics)

MKSC????

It's hard to say. Every track in the original is full of greatness. Almost every track on Super Circuit is good. Every Bowser's Castle is good. Every Rainbow Road except the N64 one is good. Most N64 and Wii tracks are awful. Double Dash and DS were generally decent. One of my favorites is Luigi's Mansion from DS.

I could more easily compare battle mode courses since there are fewer. I've unfortunately never been able to play Super Circuit's battle mode, so excluding that one (and excluding Wii because the courses are much too huge and boring), my favorites are:

Water course (SNES) -- I forget the actual course number
Ice course (SNES)
Block Fort (N64)
Luigi's Mansion (GC) -- or at least I think that's what it was called

I still don't get why people don't like the wii courses??
Anyways, what system is Super Circiut for??

Because they are too wide and bland, and just not challenging.

Super Circuit is for GBA. For fans of the original Mario Kart, nothing comes closer. I really loved Super Circuit, but since it was a GBA title and no one else had it, I was unfortunately not able to enjoy it to its fullest in versus races and battle.

My personal favorite is Rainbow Road (wii). I just love that course and i can post the best times on it. As for the argument that the wii courses are bland/too easy/boring, what are you talking about!? I love the tracks in the wii version. The only other version that may surpass it is MKDS and that's by a small margin. Oh, and i also love the airship course from the ds!

SMK - Mario Circuit 2 (is that what the final track of Mushroom Cup is called?). It was always great shooting your opponent with a red shell on the final lap so they have to repeat the lap! I love most fo the tracks in this game!
MK64 - Wario Stadium and Yoshi Valley. I like all the tracks in the Star and Special Cups.
MK Wii - I either really like some of the tracks or really hate them, but i like Koopa Cape, DK Snowboard Cross, and Maple Treeway.

@Adam- I agree the courses are wider, but I think that was just to accommodate 12 players. But how the courses are bland, I don't get. They have the most obstacles, and are extremely variegated!

Also the reason I think the courses aren't so "challenging" is because the controls for this game are easier in my opinion than any other MK.
With wider courses and easier controls, your right, their less challenging in that aspect.

@Ricardo
If all your favourite tracks are DS, go for it.

@Kizzi
OK, I haven't played MKWii for a long time now, but an enduring memory of playing that game was Maple Treeway where the wigglers were. It was like a massive field and the obstacles (wigglers) were pointless, it was so easy to avoid them. Playing the Wii version I felt so often that I was driving a bus down a country lane. On so many of the Wii tracks I had little notion of speed or scale because I just seemed to be driving across a vast expanse. Until I unlocked the bikes I was nearly bored to tears. This is one of my more minor faults with the game, but as long as you enjoy it (and I know a few who agree with you) then don't worry about it.

@Adam
I only like SNES & 64 battle modes.

Baby Park.

I'm only half-joking. It's not something that you can point to as an example of brilliant level design, but when that level screen came up during a heated 4 player match on DD, you knew you were in for a few minutes of frantic, uncontrolled item-mania. A bold track for Nintendo to include in the game, and also a good place to show your sliding / boost skills.

I also love the pinball level on the DS, and the enormous stadium (Waluigi's I believe?) on DD.

@kizzi and others
Yea, what Cow Launch said about the Wii tracks. Also, I understand they're maybe wider because of 12 players, but how often do you have all 12 concentrated in one area? It really has little effect on the race except to make it easier than necessary-- which is fine because I know it's meant to be more accessible, but that also means I'm less interested. There are definitely not more obstacles, either. Try Super Mario Kart for some obstacle-laden fun.

@Cow Launch
Yea, those were the best battle modes by far. Wii's battle mode is just not fun at all. DS's is kind of fun due to the blow up your own balloon with the mic mechanic, but the levels aren't that interesting. The Bob-omb mode in GC was kind of fun for awhile, and that Luigi's Mansion course really needs to be revisited. I think Super Circuit's battle mode is supposed to be essentially just like SNES's, but sadly I haven't played it.

@Adam- I agree with you. The courses are a little to wide, but that doesn't take away from how outstanding the game is! I think NIntendo tried to make it easier for everyone, unfortunately. I still think MKWii has alot of obstacles, compared to all the other MKs I've played(MK64, MKDD), so I still need to play SMK though to be sure.(SMK was a little before my time) Waiting for VC

SMK: It's been too long since I've played it. The only one I know for absolute sure that I despise is Choco Island 2; i hated that one back when I was younger and I hate it now in MKDS! DDD:

MK64: I love Toad's Turnpike and Banshee Boardwalk ... hell, i love all of the MK64 tracks because I played it so much when I was younger. Wario Stadium was good because you had the chance to jump that wall and blow everyone else away... it wouldn't work half the time, so there was still a chance you'd be able to win the normal way if someone was attempting to cheat that way, hahaha.

MKDS, the Waluigi Pinball and Airship Fortress tracks are really great. I would have to say the only one I'm not terribly thrilled with is the Luigi's Mansion track, mainly because of that swamp you get slowed down in. Tick-Tock Clock is also interesting; the gears can easily knock you out of your racing groove if you're not careful.

Delfino Plaza on DS is awesome. I was the only course on Wii that I actually really liked because I could boost literally the entire course and of course its fun to snake on the DS.