Day one - Start at the Louvre (free first Monday in every month) to see the Mona Lisa and Venus de Milo at least. Off to Pont Neuf - down the stairs at the statue for a cheap one-hour ride on the Seine. Boat trip brings you back to Pont Neuf - back to the metro line one (yellow) to Chares de Gaulle Etoile change to line 2 (blue) to Pigalle. Arrive at Pigalle, exit station to the right and take lunch/dinner at La Marmite. Walk up to Montmartre to the Sacre Coeur and lovely views of Paris. Back to your hotel cos you'll be pretty tired.
Day two - Eiffel Tower for 09h00 to avoid the queues (though in Oct you should be OK). Metro to Charles de Gaule Etolie, go up the the top of the Arc de Triomphe and then walk down towards Place de Concorde (check the website as I can't remember the name) and turn lef for a few scoops at Charlie Birdy's. Off on the metro (line 12 - green) to Montparnasse. Go the restaurant on the Rue de Stanislas and ask for the veal. If you've got time take in a French film at one of the many local cinemas or back on the metro to Pere Lachaise cemetery (in the east of the city) to visit the graves of Chopin, Edith Piaf, Oscar Wilde & Jim Morrison.