For me, it has to be Sao Paulo. Maybe it is because it is the last race of the season, but it has had some great races. The classic nail-biting grand prix of 2008 and 2012 were some of the most exciting the sport has ever witnessed.
I would say Shanghai should be well up there. There hasn’t been a dull race since the Chinese GP moved to the start of the season (admittedly aided perhaps by early season unpredictability). Classic circuits are great places to just watch a car blast around the track, but they sadly don’t always produce thrillers (Monaco, Spa and Monza this year, for instance).
The previous years pointed out that the first races always produce exciting races. Partly because of track layout, but mostly because of the time the teams need to adjust to new cars, new tyres and new regulations. As a consequence: when that settles in, there is ‘always’ a period mid season that some races are quite dull (worsened by Tilkedromes). Then, at the end we often see spectacular races again because of layout of Suzuka, Brazil (also weather related) and (hopefully) Austin.