If I wanted an unbiased answer to that question, I wouldn't go asking it in the Morrowind forum.
But you're still going to get one from me. Shouldl you get Morrowind? Maybe.
Morrowind is not better than Oblivion in every way. In some ways it is, in other ways it isn't. I personally think that overall it is the better game, but there are a lot of people who prefer Oblivion. Have you played Oblivion? If yes, then you can read http://www.uesp.net/wiki/Morrowind:Morrowind_for_Oblivion_Players to get an idea of the differences.
Morrowind is older and because of that the graphics are more primitive. NPCs don't interact with each other unless a script tells them to do so. They only interact with the player character. Compared to Oblivion the animations are worse, the combat is clunkier, and stealth isn't as good. NPC mostly stand in the same spot 24/7, though some might wander around a little.
But on the other hand the art direction is better (or at elast I prefer it), the factions interact with each other, there is a lot more of them (apart from the 3 standard guilds you also have the Imperial Cult, the Tribunal Temple, the Imperial Legion, 3 different noble houses, the Morag Tong assassins, and with the Bloodmoon expansion you can even join the East Empire Company). There is also a lot more different types of weapons and armor and the world in general is richer and much more sensible. There is no level scaling and the creature leveling is much milder. There is no such thing as common bandits wearing Glass Armor and using Daedric Weapons. Rare items are actually rare. You can find hand-placed artifacts if you explore on your own. There are functional mines and fishing villages. And the Dunmer have a very strong culture.
In short Oblivion is a more convincing presentation of a less convincing world whereas Morrowind is a less convincing presentation of a more convincing world. If all you want is some dungeon diving action you'd better stick with Oblivion. But if you want to explore a fascinating new world Morrowind is the best.