I agree with Bruno. The extended editions of the LOTR trilogy really add a lot. One example is just how much more Gollum gets tortured and abused after swimming in the "pool" and catching fish. He is happy-go-lucky (albeit split personality still) and seems to like Frodo. Then in the regular edition, you just assume that because Frodo was there when he (Gollum) was captured that now Gollum's more evil personality comes back and he is pissed off.
In the extended edition, you see why.