Hm, interesting opinions here. I would consider Skyrim as a vast improvement over Oblivion in nearly every way. The world feels more full for one (It's not so many tracks of forest and plains, there's more variation in the landscape), the dungeons each seem more unique and there's more tangible benefits to exploring (Oblivion's dungeons to me always felt more copy pasted, and the loot was far too level restricted to be much useful collecting).
Also, there's more going on in the world besides the main quest, more which also relates to the main quest but isn't a part of it. One thing I remember in Oblivion was outside of the main quest, there were few references to the daedric invasion. In Skyrim you have the legion and greycloaks, the dragon priests, as well as the random bounties (Which I like a lot, it's nice to see some randomisation of quests reimplimented) all relating back to the dragons.
Whether I would consider Skyrim better than Morrowind? Well... it's too difficult to compare them. Morrowind is quite old now, and within the limitations of the time it was awesome, but I play it now and (1) I walk and run SO slowly, (2) The combat was an awful holdover from Daggerfall and (3)... hmm... I would say the world feels so dead compared to Oblivion and Skyrim. That last one is being quite unfair though, considering Morrowind came out in 2002.
Bah, whatever. To me Bethesda have gone up and down in the quality of their games over each iteration.
From a dip with Oblivion (despite all the hours I have in that game) to steadily rising again with Fallout 3 and New Vegas, Skyrim fixes all of the problems I had with Oblivion. I have 160~ hours in Skyrim and really the only reason why it's not higher is because I've been pacing myself. I could have finished it all within the month of getting it, but I enjoy things more if I come back to it and things are all hazy and I can rediscover them again. As it stands I still haven't finished the main quest and I have four different characters on the go.

Edit: Oh, except the UI. That was a mess. Mods for the Mod God!