The bigger you make the world, the less detailed everything in it is, which is probably a serious problem when it comes to your big, free-roaming RPG. Daggerfall was huge, but there wasn't much meat behind a lot of the stuff. Morrowind and Oblivion went for the 'smaller but more little details' thrown in approach, but I agree it'd have been nice if they'd had a bigger land area and more 'neat little options' like Daggerfall.
Which of those games is the best...I can argue with myself for hours over that, much less someone else.
