I will be in Barcelona, Madrid, Seville, and Jaen & Ronda (paradors) in early November with my girlfriend and would like some of your expert advice on where is the best or most romantic place to propose? Thank you in advance for any suggestions.

The town of Montserrat is about 30 minutes from Barcelona; the views from their ancient monastery are breathtaking, the quietness and the splendor of the sorroundings are marvelous. The monastery and museum (Picasso, Miro and others) can be reached from the bottom from a Tramway and also a cable car.
Of all the stuff that I saw in Europe, Montserrat has to be on the top three, no question about it.

Good Luck !

At the top of Catedral de Sevilla (Cathedral of Seville). Spectacular backdrop!

Try to book a room with a balcony over the gorge at the Ronda Parador and wait for the sunset! If they say one is not available, contact the hotel manager and tell them of your plans...

You are truly a gem! I'm sure she'll say "yes" where ever you decide!