I mostly negatively critique Morrowind, I wont say a single bad thing about Morrowind however inviting it might be, and here's the things I really enjoy about the game.
I could name most of the usual stuff that Morrowind does right, like the diverse guilds/weapons, which I enjoy, but we always hear about that, so I'm gonna say some stuff that we don't usually hear but that I really enjoy in Morrowind.
In Morrowind, I can block a magic missile mid-air with an arrow, did you know that? I've never experienced that in OB but it sure was awesome when I did it in Morrowind.
In Morrowind, Argonians actually swim like a crocodile, yeah I know, it's not such a big deal, but I found it nice for roleplaying purposes.
I really enjoy that you could get your own tower, or place, sure you could as well in OB (DLC), but in MO it was a reward, which was nice, you felt you had more respect in the guild.
Here's an obvious one, beast legs, I like playing the beast races, so the beast races made me more unique.
Beast voice acting accents, in OB they still have some accent, but in MO it's stronger, it more foreign, you can almost here the khajiits purring when they say some word with an "R" in it, also with there foreign sayings.