My favourite airport : Hong Kong would have to be one of my favourite airports with Changi being a close second.
What I like about it:What impresses me the most about HK airport is the openness of the space, the use of natural lighting, softened by the intelligent use of reflectors and the curved high glass ceiling. Also, there are great food options and good connectivity within the airport and I have found that the facilities work all the time.
I love how you get a good view of the spectacular scenery surrounding Chek Lap Kok. If I had a long layover, I would choose HK airport simply because of the excellent lounges, the business amenities, the user friendliness and the general vibrancy of the whole space.