The scouring was an unnecessary part of the book and would have made the endings impossible. Would you rather have the scouring or all the other endings which, IMO, were necessary? It just didn't work on film, and I understand and respect that.
Some cuts that sucked, however, mostly from the list just given (haven't seen RotK yet):
Spoiler:
The death of Saruman
The choices of Master Samwise -Both of these should have been in the TT movie instead of the RotK, especially Saruman, if his death was an ending for TT instead of a beginning for RotK to paraphraze PJ. If that's the case, why wasn't it in the TT?! For all the endings to RotK, or so I hear, the TT ended rather abrubtly and nowhere near accurate to the book. Of all the decisions PJ made this one I understand little.
Houses of Healing/The romance between Faramir and Eowyn (which is only hinted at, at the very end) - this is almost necessary, because they are both major characters that need closure. While an in-depth thing isn't necessary, they should have at least done at least a 5 minute segment. It also gives Aragorn much needed screen time and character and plot development.
The mouth of Sauron -
Would have been nice, don't see why he was cut, but although I don't understand the reasons not the biggest deal.
Confrontation between the Witch-king and Gandalf -
What the hell were they thinking?!?! It would have taken a whole minute and a half.
And Merry pledging loyalty to Theoden -
Once again, what the hell were they thinking?! A critical moment, and the love of Merry and Theoden is great.
And Eomer grieving at Theodens death -
Why would they cut that? That just makes no sense to me.
At least they'll be on the EE DVD, but that can't be a constant excuse. Most of the things mentioned here are not big at all (except for the house of healing/Faramir and Eowyn, and that's OK to be saved for the EE DVD.)