I prefer Morrowind, but you have to be aware that it's a bit different genre. Oblivion and Skyrim are action RPGs, while Morrowind is just a RPG. Because of that it may be a little frustrating at start, that you are not able to hit anything (people often cite this as a reason of Morrowind's inferiority, even though you need only few hours to get over with that "you are shit" phase), but everything else is worth it. Just immerse yourself in that unusual world, explore it, get to know more about it. Also, if you can't stand the graphics (they are not that bad though, for me that game is fairly pretty) there are lots of graphics mods making the game look even better than Oblivion or Skyrim, or at least that's what I hear, never used any. Another major difference is the fact that most of what npc's say is not voiced and the dialogue system looks like wikipedia article. That may be a little offputting, but thanks to it they have much more to say.
I would say that the choice should depend on what kind of person you are, what do you like. For me, Skyrim's vikang style is just plain and boring, but it is most certainly more action packed than Morrowind. Just look at a fight in Morrowind and compare it with one from Skyrim. Yeah, there's quite a big difference. Though, if you don't care about fights that much and you'd rather immerse yourself in a fantasy world, Morrowind does much better job, even with the old graphics.
Well, whatever you pick, enjoy it, focus on the things it does great.