I think Baldur's Gate had an attractive inventory interface, but it was not very functionally designed. First of all, it was too restrictive in terms of space - and the UI screens were all opaque, taking up the entire area.
Neverwinter Nights was miles ahead in terms of functionality, and it was a lot more lenient with inventory space. Also, it was transparent and non-intrusive.
The radial interface received a lot of flak, which I don't understand. It was never meant as your primary way of interacting with the game, merely a base from which you could access everything. You had tons of hotkey slots, and every primary function had a corresponding hotkey.
Overall, i'd say the NWN UI is one of the best i've seen for a game that complex, and I have no idea why it was criticised so much. Apart from aesthetics, it was superior to the NWN2 UI in just about every way.