Good game with some flaws.
Another title in Elder Scroll series, that is easy to recommend to a RPG player.
Gameplay
There isn't anything unique in combat there are strong attacks(Hold RT), weak(Pres RT), block(Hold LT) that's it, kind of boring, but when you defeat an enemy he falls in a very satisfying way that makes you ignore the boring combat. Mage thou is very different from a warrior and I think it's more interesting being a mage, there are tons of spells, not to mention you can make them, also casting spells is more satisfying then sword combat.
World
Oblivion is a sandbox, open world game and it's huge. There are dungeons, city's, villages and an Arena everything that you expect and that's what makes exploring really fun. But don't think the world is perfect, when you enter a city you will feel that the city is a bit dead, everybody are just walking like they have nothing else to do, the game defiantly needs more noise in city's. The world also changes depending on your level. Example, at the beginning of the game you will mostly run into wolves and other week animals, but when you reach lv 20 you will start to run into Trolls(They are defiantly one of the strongest creatures). NPC's have a schedule, you will see that in the morning they will leave there homes and do there stuff. The game has allot of items(Ingredients, weapons, armor, scrolls etc.). There are also factions you can join(Mages Guild,Fighting Guild, etc.), to me the most interesting is Dark Brotherhood.
Quests
Quests sometimes gets annoying, because they are always marked on a map and you are always runing from one place to another, personally I prefer Gothic way(Find your way)
The main quest is very short you can finish it in the mater of hours, I recommend joining factions if you want good quests. There are also unique quests, like travel inside a painting or going inside a mans dream.
Vampires
Allot of people may think that it's awesome, but they are wrong, when you infected with this desise, you will start transforming in to a Vampire your skin will get pale etc. Now for the bad news, when you will become a complete Vampire, you will burn in the sun like crazy, allot of shops wont sell goods to you, so it's very hard to survive as a Vampire(Don't worry there is a quest for cure).