[Purist]

Just doing some quick checking on the listed circuit capacity, I think every one of those top 10 just about must be inflated, except, maybe, for Mexico.

The Russia figure is also definitely inflated, and I suspect the Azerbaijan one is somewhat artificial as well.

Italy, Brazil, and Japan seem like possible, if not probable, low-ball numbers. And I strongly think the listed capacity for the Red Bull Ring is inaccurate on the low side.

Aside from track capacity, you also have to, to an extent, consider the geographic and/or population size of the nation in question, as well as how many of its nearby neighbors have a GP.

One way to look at it is this. The European rounds, aside from Russia and Azerbaijan, all seem to draw rather well, and likely have a higher proportion of paid ticket sales than some of the other, much newer events. On the other hand, China doesn't even draw a full one-day audience, when looking at the circuit's theoretical capacity of 200,000, and this is in a country that is how large and how populated, near one of the most major and developed cities, and the only F1 race within how many thousands of miles on the Eurasian mainland.

I mean, shoot, Australia draws better, and it has fewer people in the entire country (also continent) than does the city of Shanghai on its own.

But anyway, changing gears here, I'll address another matter that Crmalcolm was harping on.

If I'm rating current/recent F1 circuits largely on how enjoyable I think the racing has been, this is roughly what I get:
1. Spa-Francorchamps
2. Interlagos
3. Red Bull Ring
4. Montreal
5. Melbourne
6. Suzuka
7. Monza
8. Baku
*(Somewhat optimistic estimate if Buriram were to join F1)*
9. Istanbul**
10. Sepang*
11. Singapore
12. Silverstone
13. Hockenheim*
14. Austin
*(Conservative estimate for Zandvoort)*
15. Hungaroring
16. Catalunya
17. Shanghai
18. Mexico City
19. Abu Dhabi
20. Bahrain
21. Buddh**
22. Sochi
*(My fear for Hanoi)*
23. Valencia**
24. Yeongam**
25. Monte Carlo

Keep in mind, I'm trying to compare like to like, which means the odd wet race has to be regarded as something of an outlier if the circuit in question normally doesn't produce that level of racing intrigue.

Also, non-permanent circuits that manage decent racing may get a bump up; on this note, Singapore would be higher, but the changes around the Anderson Bridge have definitely hurt the racing there in the last few years. Baku might also be higher, but for the absurdity of having DRS, at least on that 2.2-km front stretch.

In addition, if the circuits are close enough in racing terms, I may clump them, but the order they're in may not be a totally precise thing.

So something like:
Tier 1: 1-3
Tier 2: 4-8
Tier 3: 9-12
Tier 4: 13-16
Tier 5: 17-20
Tier 6: 21-24
And Monaco is in a class all its own.

And then, with a circuit like Istanbul, it's hard to know exactly how things would go with the current cars, but I don't think the racing now would be any worse.

Finally, on the bright side, some of the worst ones didn't last a terribly long time.