A-
Pros:
Huge and Immersive world.
Amazing scenery.
High Re-play value.
Teary eyed moments.
Alot of quest diversity.
No noticeable copy-pasting.
Enjoyable combat system.
A few decent puzzles.
Great effects!
Near perfect optimization (for xbox360)
Great Charecter customization.
Intresting new insights into the lore of Dwemer and Falmer.
Cons:
A few skilltrees serve no real purpose, and the game would have been better of without them.
Magic skilltrees force you to choose ALOT of perks you might very well never have use of.
Destruction feels slightly pointless.
Map sometimes act strange, making it difficult to get where you want to go.
Civilwar quests and questline feel small and gimmicky.
Most Unique items can never measure up to non-unique crafted items.
The "guilds" "endings" seem unrewarding and forgetable, and sometimes non-existant.
Dragons are far to common, and are generally weaker then high lvl mobs, such as the Draugr Deathlords other the Dragonpriests, both of which are supposed to be servants of the dragon..
Some of the highest level Vampires mages are absurdly powerful to the point where you wonder why they are not known as the world eaters rather then alduin.
To few things to spend gold on, in the end you will have so much gold it makes you wonder why you are not allowed to buy a fort for yourself.
No ownable houses/cottages/villas outside of the cities, some of us are hermits you know, not to mention it would be nice to have a place to call home that you don't need to zone twice to get into.
Thalmor did not seem nearly as dangerous as they were portrayd, the most dangerous part seemed to be theyr ability to blind you with the amount of fire and shock spells they used

.
Horses does not feel like a big upgrade from running, the controls dont feel right, it takes to long to unmount, and they act like lions not horses.
Lycantrophy and Vampirism both seem gimmicky and unrewarding.
There are many pros and cons but in the end i still spent well over 100 hours playing the game, and I would be lying if i said it was not enjoyable. anything below a b+ would have been hypcrisy for me..