Any examples for MW quests with more than one possible outcome? The only two things I can remember is that if you did a certain Fighters Guild quest before you joined the Thieves Guild then joining the Thieves Guild would become impossible (that's what I remember at least, and if you joined the Thieves Guild before that point you could do both questlines). And you could only join one of the three (available) Great Houses. But other than that MW quests didn't have any choices I can remember.
EDIT: It's been a few years since I played MW the last time, but back then I played about 95% of the quests and I can't remember anything like that.
Well, I can only name a few (it's been a while since I played Morrowind also), but even so its quest were far more involving. Morrowind had more interesting and deeper quests, while FNV had more possible outcomes.
One of the best quests ever in any RPG to me personally was in Bloodmoon where you had to start the Raven Rock mining camp. You literally started with an empty patch in the forest, you then had to lead the first miners there to safety and get them the necessary equipment from the crashed supply ship. All the while you could choose to aid the mining camp or the imperial officer who didn't want it to succeed. And every few steps further into the quest you would actually see the village take shape, first some wooden scaffolding, then a few houses, and then a fully functional mining camp with shops and taverns!
It really gave you a sense of progression and consequence that few RPG quests have. And as far as main quests are concerned, Morrowind really had the best, you had to complete so many steps before you were even recognized as Hortator/Nerevarine. You had to win over the different houses by completing different quests (not like in Oblivion where you simply had to close an Oblivion gate near a city to gain a few extra soldiers at the final battle).
FNV also had much better writing and dialogue compared to Oblivion and FO3, and it really forced you to choose factions.