I love pampering my nobles, but not too much.
I make a Nobles Level, around a similar level to the main upstairs tavern. If I can find marble, I choose a marble level, and make a central open area with a private well, some statues, and smoothed floors with engraved walls. The Nobles offices open into this central marble courtyard, with private dining rooms and bedrooms adjoining each office, and more bedrooms and tombs along the far side. I usually put in a private staircase to the main tavern, so that they can collect food when they wish to. If I choose my moment, I can lock all the nobles down their in their own marble gilded cage by locking a hatch. Their rooms are full of useful items, such as chests, armour and weapon racks, and there's usually a pick stockpile, ever since a nasty accident with a werepanda. Usually I make a few too many fancy rooms, and just assign them as and when necessary.
...then there's a row of rooms with long corridors with lockable doors, levers, floodgates and grates that don't appear to do anything. I don't recommend going and looking at that end of the Nobles Suite, it's mostly irrelevant anyway. And you never made a mandate which wasn't for The Good Of The Fortress, right? Ever since the Great Catsplosion of 542, I've referred to that end of the hallway as "the kitten suite" anyhow....