Of course the Vanilla game sucks. However... With mods I can make my game whatever I want. Difficulty? Sure just use Morag Tong Hunters so that every once in awhile the Morag will hunt you down to slaughter you. Graphics? Sure just get some textures. Houses? Hell you can make your own house quite easily wherever you want it to be, So basically, yes without mods Oblivion is a bad game. With mods, however, it is the best game I have ever played.