One of the best-looking, biggest, and, more importantly, best RPGs out there. Massive doesn't cover it.
Gameplay: The main story revolves around a cult called the Mythic Dawn, a group of daedric (the opposite of the gods, the Aedra) worshippers who wish to take Tamriel (the continent where the series is set) for their Daedric Lord, Mehrunes Dagon. To do this, they needed to wipe out the bloodline of the Septims (the royal family) so they could open Oblivion gates and enter Cyrodiil (the part of Tamriel the game is set in). To close the Oblivion gates, you need to follow the main storyline to find Uriel Septim's (the current emperor) lost heir. While doing this, Oblivion gates will pop up over Tamriel, which you need to enter and fight your way through to close.
This is the main storyline. However, after completing a bit of the story, it will be well worth it to ditch the main story for the time being, and do a lot of the rest of the game. There are four main guilds: the Mages' Guild, the Fighter's Guild, the Thieves' Guild, and the Dark Brotherhood, the assassination guild. The first two can just be signed up to, but the other two involve a bit of crime to get in (go to prison to join the Thieves' Guild, kill a civilian/soldier to join the Dark Brotherhood). The four guilds are very good, with the Dark Brotherhood standing out as the best storyline. Then, there a heaps of side-quests. A bit of asking around or exploring might lead to a side-quest, characters might approach you to do a quest for them, and there are also the Daedric side-quests, where you make an offering to the Daedric lord, do a mission for them, then get rewarded with a Daedric artifact, many of which are very useful. The gameplay is excellent, and makes this game so good.
Graphics: The graphics are excellent, with super views of the landscape, dark dungeons, and hellish Oblivion planes. The characters also look excellent.
Sound: This game comes with very good music, and excellent voice-acting. The music sets the tone perfectly, and really goes.
Value: The game is absolutely massive, and with so much content, is really worth your money.
So, all in all, a massive game with excellent gameplay, graphics and sound. I won't this game a 10, because it is not perfect, and my interest had waned by the end (I left the game for a couple of months, then came back just to complete the story), but it is very close.
Score:....9.7