@katliamom - it’s multicultural and vibrant, restaurants and wine caves are incredible, it’s close enough to other stuff, and a good friend of mine is a short metro ride out 
Last time I stayed in Belleville in the 20th, and loved that area. The 11th is great, too.
I like 11th too, and 12th. There’s an area there with a lot of stores that specialize in decoration, upholstery, carpentry… I love walking along there and looking through the store windows.
As long as we are recommending farther flung arrondissements – when I was in Paris a couple of months ago, I stayed at my friend’s place in le 16e. Very chic et snob – residential area with beautifully dressed matrons and stately Art Nouveau town houseS. Super neighborhood feel. I wouldn’t recommend it for a first (or second) visit but if you are comparing and contrasting it is a good contrast. Marvin would hate it; pretty much the opposite of the 19th!
When I lived in Paris, I lived in the 16th. I don’t think I ever even explored the area. I was always hopping the Metro over to the more lively arrondissments. Now I’d like to go back there and check it out.
I knew a couple of French kids whose parents lived in the 16th… so posh they were a little embarrassed to say where they grew up. It’s fun to occasionally see places like that, even though it inevitably makes me feel like a peasant. OTOH, so would staying at the George V, but I still wouldn’t turn down an opportunity to do so
Another vote for Airbnb. I’ve stayed in a couple of different places in the 7th, in the area between Invalides and Tour Eiffel, in the vicinity of the American University of Paris where my D was studying.