Some original thoughts, original graphics, very much grinding (argh), no real interaction with the world (politics, possibility to change story or events through your actions), a friendly community and a lot (relatively speaking) of good and interesting roleplayers.
In all probability one of the better mainstream, big MMOGs, if not the best. Certainly the RP is great, which is the most important thing for me. If the game and gameworld itself supported roleplay and didn't focus on grinding so much, it would be even better though, but for that, we'd have to look for other games, such as possibly URU Live.
Right now though, there's the tiny problem with SoR that the firm behind it is undergoing bankruptcy, and they need another firm to take over very soon, or it'll all fall apart. New players can only play on the newbie isle (which is a great place as such, though probably lacking in RP) and not go to the mainland, until this is resolved.