There are a lot of great, small hotels in the 6th - especially around the Odeon Theatre area. The Luxemburg Gardens are right down the street and while nice - you can do better in Paris for a proposal. There are some pretty and quiet spots up in Montmartre that look out over the entire city. I even heard accordian music up there once! It was like being in a movie. Back to hotels... sometimes a 2 star has very little difference from a more expensive 3 star. Some names.. Hotel Rive Gauche, Hotel Jardin de L'Odeon, Hotel des Balcons. And if you want a good but not over the top dinner - L'Epi Dupin is terrific.