I'm surprised that so few people have finished the MQ. I figured that with Morrowind being available for the better part of a decade that more than 3/4 of it's players would have (those that voted here anyway.) I suppose it's just another testament to the games epicness. :twirl:
Well, I only own the game for about a year now. But yes, I tend to play it in binges, and one binge is not enough to finish the entire main quest. After the binge, I forget what this character was supposed to do and roll a new one instead. The low levels are the most fun anyway.
As for Oblivion, which I do own a couple of years by now, I only finished the MQ once. I was badly disappointed by it, so I never really felt compelled to finish the MQ again. I follow it up to the point where Oblivion Gates open all over the place and just leave it at that point, normally. Speed-clearing those gates is a hobby of mine.