As other people said: just look at Dragon Age: Origins.

What I want:
- one special scene before the last battle at the camp with all our companions (and allies), talking about the future etc... (it is ridiculous that you have any kind of discussion ONLY with the one you take with you for the battle). Special attention to the scene with your LI.
- The Battle
- A party to celebrate saving the world (throne scene in DA:O), with interactions with all the major character in the game (and obviously a special scene with your LI)
- Ending Slides that narrates all the consequences of your decision (DA:O, Pathfinder etc...)

Ending slides were the MINIMUM to make the ending ok-ish, right now the game is one step below DA:O.
But this (one last night before the battle + post final battle party + ending slides) is the ideal ending the game deserves.