Opinions vary... obviously. I was trying to give a different point of view in my opinion on these games other than the normal "Dis game is funnerrr den dat game." (And for the record, I LOVE to back myself into a corner in GTA, punch in weapons codes, and kill everything in sight for hours and hours... hell, who doesn't?!?)
You don't have to explain to me that the #1 reason why people play video games is to have fun. Hell, I'm not a moron (even though some may argue that).
If we're going by our individual opinions and being honest here, then I have a ton of fun playing Mario Kart. Yes, the tracks are better and the weapons system is advanced in the Wii version of the game, as compared to the SNes version. Hell, I would hope so. Usually, game sequels should be better than their predecessors. And for players that love racing games, this would definitely eat up many hours of their lives.
So, since we can actually agree that the purpose of video games is to have fun and both of these games are fun in their own right, where do we go from here? Unless we look deeper into these video games besides their "fun factor", we'll be at a stalemate. Why, you ask? Because there are many people out there that find role playing games to be more fun than racing games, and vice versa. So what is your "fun factor argument" proving? Not a whole lot here. Personally, I enjoy role playing games a lot more than racing games. But I won't allow my decision to be based on that, alone.
Even though Mario is a LEGENDARY franchise, the Mario Kart games will never hold a candle to the Super Mario series of games that almost monopolized the gaming industry at one point in time. And the thing that made those games so addictive and popular is the advancement in it's complicated levels, it's graphics, it's difficulty, and it's fun throughout the game's entirety. Mario Kart does possess some of these factors. Its tracks become more difficult throughout the game, but I don't see much more than that. To me, you're still racing against the same opponents and using the same weapons.
On the other hand, Final Fantasy made leaps and bounds over its predecessors. Its difficulty, brain-teasing storylines, graphical enhancements, connection with its characters, and newer features from its earlier games are what made it a legendary series. This particular FF game introduced an addictive storyline similar to a big screen movie, a multitude of new characters, a difficult and time consuming magic-learning system, an advanced "Summon" system (i.e. an inter-game magic spellcasting system that TRULY made the FF series rise above all other role playing games), and an introduction into side-quests and alternate game-endings. Not to mention these endings were superior over the objective of just 'catching a checkered flag for the 20th time'.
To sum this up for everyone reading, deciding on your favorite game in this series has to start with what type of games someone enjoys. Then, you have to figure out how much fun you have while playing the game, which depends on the type of game you like playing in the first place. After that, the decision is in the eyes of the beholder.
If you only look at a video game by how much fun it is, all arguments will become stalemate, eventually. The only way to make a true and justified decision between better videos games is to look beyond all of that. Previously, I chose to use intelligence as one of my factors. Gee... shame on me, right? But this time around, I believe I've given more concrete arguments that would even satisfy 48.7, wouldn't you agree?
Bottom line: Final Fantasy 6 is better, period. So vote for it.