After a while of playing around with Super Mario Kart, I've changed my opinion of it: I like it, best in the series (can't say about MK:SC as I gave that away). At first I thought the slip-sliding made the karts too slippery, but it seems like it gives the karts a real sense of momentum. Mario Kart 64 meanwhile has much less of that feeling - you feel a lot more in control of your kart, but then it's not as fun. Not much compares to successfully drifting through a tight corner. And I always thought Super Mario Kart had the best tracks regardless. More colorful, more Mario-like (it lost something in the move to Mario Kart 64 as it looked more realistic and serious, probably why MK:DD went back to the cartoony look). The tracks seem pitifully short now, Rainbow Road in particular (probably why you had to do 5 laps), but... who cares about length when I still find them pretty difficult. Especially Donut Plains 3 as the opponents keep leaving me in their dust.
And Koopa Troopa rules.