Released by Bethesda Softworks in 2002, Morrowind is the third game in The Elder Scrolls series (the first two were Arena and Daggerfall). It is available for both the Microsoft Xbox and PC. There are two expansion packs available for the game, Tribunal and Bloodmoon, which are avilable for the Xbox in a "Game of the Year" edition. The PC version offers some extremely sophisticated mod support (through a "plug-in" system) and a very powerful set of modding tools.
The game is a non-linear role-playing game (RPG). The game mechanics are a little different from most RPG titles in a few important respects. The first, and most noticable of these, is the first-person perspective. (I should mention that I have never played Arena and have only played Daggerfall a little bit. Thus, I can say that Daggerfall also featured a first-person perspective, but I don't know about Arena. Tabs informs me that Arena was, indeed, first-person as well.) Secondly, the player's skills simply improve through use (jumping a lot will improve the applicable skill, as will sneaking improve sneaking, using weapons will improve that weapon's associated skill, etc). Dungeon Siege boasts a similiar system, but Morrowind has these two very important differences: the improvement is much more linear (gaining each point is almost as easy as gaining the last), and the skills affect things other than weapon and spell use (things like wearing armor, stealing, creating potions, etc). Most other RPG's improve the player's skills through a standard experience system (killing bad guys nets experience points, which eventually allow the player to rise in levels). Morrowind does have player levels, but leveling up simply occurs every time you gain 10 of your major or minor skill points.
The third major difference from most other RPG's is the freedom granted to the player to do whatever they like. The game world of Morrowind is an island called Vvardenfell in the province of Morrowind in a vast Empire (simply called "the Empire"). Let me say this again: the game world is a 1:1 scale model of a fictional island large enough to boast about half a dozen major cities and a couple dozen small villages, with space left over for a wasteland and countless ruins, tombs, and dungeons. Oh, and there are also hundreds of tiny little islands surrounding the main one. In addition to this, there are several major factions (of various levels of power and approaches to life) vying for control of the island, and you can choose to side with any of them.
You can simply walk anywhere. Or, if you're lazy, you can hire a boat (or other available means of transportation) to take you between cities. There is no limit to your exploration of the game world. The level of detail borders on obsession on the part of the game makers. Pick a random point on the map (the game comes with a fairly detailed printed map a little under 2.5' square) and there's probably something there.
Sure, there's an element of repitition, but you learn to ignore the certain parts that repeat the most (the generic town guard types, for instance). From what I've heard, it's much better about this than Daggerfall was.
The PC version, out of the box, has a couple bugs (suprisingly few on my system configuration), but the most recent patch seems to have squashed these (for me, at least). The game does not offer multiplayer; how on earth would it? The game would turn into a MMORPG. The plug-in system is amazing. A plug-in can introduce anything new: new weapons, new items, new geographical features, anything. These new things can then be inserted into the game and loaded, even by an existing savegame. Want a new island, somewhere in the southwest ocean? Go for it! Want a new, super-powerful set of armor, with its parts strewn across the island? Sure, no problem (just be careful to not displace existing things; the game supports doing this, but it might not be a good idea to do so intentionally).
I was telling my dad about this game, and he asked "What's the point? What do you do?" Anything you like, I replied, what's the point of real life?
Update 9/30/02
The webcomic Mac Hall has posted an epic comic following the artist's adventures through the game of Morrowind. It can be found at http://www.machall.com/morrowind, and I think it presents the game exceedingly well.
Update 1/19/09
The above comic is no longer available.