I could go with Jerez as an alternative to the two tedious circuits that Spain gives us at the moment... it may not be any better but a change is as good as a rest, etc.
If keeping one of the two we have then keep Barcalona; at least it is a race track rather than a run around a dockside industrial estate (now if the Valencia race was run through the middle of the city...
).
France would be good but I'm not fussed either way with Magny Cours (but that's a different thread). Paul Ricard could be good but is Bernie's ex really going to want to have a business deal with Bernie (and basically pay back that alimony settlement)?
I'd rather keep Monza than go back to Imola (I do think we need to keep to one race per country... we can't complain about Spain having two races and then give two to Italy).
Indianapolis... no; not when we have Austin to look forward to.
Fuji in its latest incarnation didn't do it for me and Suzuka is too good to drop; appreciated by fans and drivers alike.
Estoril could be good but I'm not sure it has as strong a historical claim as others and the level of Portugese involvement in F1 is nominal at present. I also don't see them having the cash and support available in the country to keep it as a going concern on the calender.
Alternatives from those on offer... A1 Ring (I'll ignore the RB bit if you don't mind) if only because I remeber some good races even after the Tilke revisions and they had some great camera work. The landscape is still great with elevation changes galore and it makes a change to have some natural greenery...