I enjoyed Double Dash, because the game felt like they brought the fun and item usage of battle mode to the full front in the races, probably because you held double the items. I didn't enjoy switching back to one item at a time, or the huge amounts of strong items in the Wii version. I just didn't like the DS version, and couldn't play it much.
Anyways, I liked the N64 battle modes, partly because of the ability for the third and fourth player to become bombs once they lose. I loved the block fort, and the reason why I like Double Decker over, say, Luigi's mansion, is that there were more pathways to take, more ways to hide, and more ways to scheme. Anyways, to me, Mario Kart 64's tracks all seemed characteristic of their environment, when you drove on the beach, it felt like you were driving on a beach, not a racetrack. Double Dash lost that, and then Mario Kart DS brought it back. The Wii version is in the middle, there, not really good or bad.
That's my two cents, at least.