Ok, on such a short notice, a quick answer is imposed...
You see TP
traffic, as well as the ocasional charter and the inter Island traffic (ATPs from SATA). The approach is over the city, so you can see the sights and do some spotting
Horta is also nice, but you'll only see TP
traffic (A319/20). And Flores is such a small island, only ATPs go there.
Now for the tourist side: The Azores are simply out of this world. I really can't help with Flores, but Horta has the Marina which is world-wide famous... Every ship that comes to port must make a drawing on the wall/floor, so it is quite colourful. Also make sure you visit Peters Sport Café, and have a gin with lemon for me there
It's a rendevouz point for travelers and sailors and a must see
And finally, the 'Capelinhos' volcano, last erupted in 1957, is also a natural landmark.
At São Miguel, naturally begin with ponta Delgada itself, there's lots to see there... churches such as the 'S. Francisco' and many great things... and the second most important thing to see are the lagoons. Make sure you visit Sete Cidades and Fogo lagoons. An alternative to the circuits already premade is to arranje a round the island trip with a local taxi driver. It's about 100kms total, and should not be that expensive. You'll have more freedoom to see things this way.
Finally, make sure you visit the 'Furnas', a volcanic area in S. Miguel, where there are some vapour geisers coming out of the land in the middle of the town, and you can taste a local food that is cooked using the heat form the earth... it's very nice (cozido das furnas).
All in all, I'm sure you'll never forget your visit to the azores. No one ever does. Enjoy!