Okay, so my idea about setting the final battle in the Imperial Capital isn't so popular, but I'd like to say two things in its defense.
Firstly, the original, I think, lacks tension compared with this idea. The Death Star is apparently not operational. We only discover that it's operational during the battle. This makes for a good twist, but it also leaves the tension very slack up until this point. The Death Star is also apparently undefended, meaning that we can expect this battle not to be too difficult, until it turns out to be a trap. This idea, on the other hand, would have the rebels seeking to assault the Imperial stronghold, which is only for the moment less defended than it usually is. It's a desperate attempt to knock out the Imperial government while they still have a minor chance of success. This possibility for success is then dashed when it turns out to all be a trap. In this concept, the tension is high at all times. At every moment, they're facing a tremendous danger, even in the best of all possible scenarios, and then the worst possible scenario - which would be the arrival of a massive imperial fleet - occurs.
Secondly, I think the destruction of the palace could not only be as good and exciting as the destruction of the Death Star, I think it could be better and more original. Take for example the conclusion of V for Vendetta, which features the destruction of the Houses of Parliament. The symbolism is clear - it's the elimination of an old order and implies the institution of a new, better order of life. If the Imperial Palace was decked out in statues of the Emperor, intimidating semi-Gothic arches and other imposing imagery, its destruction would represent the collapse of the whole oppressive Empire. It would give the viewers more reason to believe that this is a blow that the Empire can't recover from. It has lost not only its leader, but the seat of its government and likely the whole of its political class. After all, the Empire was very centralized. It's possible that they orchestrated the oppression of the galaxy from this massive base of operations.
Imagine something like this, with Williams instead of Tchaikovsky:
http://www.youtube.com/watch?v=vnPvbfogeSI#t=1m53s