Avignon

Very helpful official tourist office, both on-line and in person:
http://www.avignon-tourisme.com/home-1-2.html

Rick's At a Glance sightseeing list for this city is relatively short. There's also a nice covered market hall. Your timing sounds good - Avignon has never really grown on me as an extended-stay destination.

You mention the 2 main sights that everyone wants to 'tick off'. Others to consider here ...
http://www.planetware.com/tourist-attractions-/avignon-f-az-av.htm

Wasn't overly impressed with the Pope's Palace - it was a bit expensive for tickets, and inside is pretty empty. I wish I had seen Rick's travel talk about just admiring it from the outside and not bother going in. We did enjoy the bridge and the audio guide...

We were good with 1/2 a day there - we opted to not go in the Palace.

While we enjoyed Avignon well enough, it was really just a good base for what we wanted to see on day trips. The indoor market was a definite highlite, a good spot to get lunch and chat with some local types. It does shut down shortly after lunch IIRC. We skipped the Popes Palace on advice of Forum members.

I echo what others have said -- we enjoyed just walking around but it is not a place I would do an extended stay. It was convenient for transportation (high speed train to Paris, and pick-up city for a 1-week bicycle tour of Provence). We did not go in the Pope's Palace, but walked through the garden. We looked down on the bridge and that was fine for us. We enjoyed Nimes much more, as well as other areas of Provence.

You could go to Pont du Gard. Stunning former aqueduct in the countryside, great walking along the river and up to the hill with views of the aqueduct and countryside.

While based in Avignon for a couple of days without a car many years ago, I took a very short train ride to Orange to see the (still-in-use) Roman theater. That was by far the highlight of my two days in Avignon. It's breathtaking.

Bets is right - the Roman Theater in Orange is breathtaking, with its huge intact theatrical wall. The rest of Orange is a bit grungy, however.

Unless seeing massive piles of stone from the inside, with totally empty insides, is a high priority, skip the Palace of the Popes. It literally is just bare stone walls. And the audioguide for it is one of the worst I've ever used. Instead of tales of history and intrigue that it should have discussed (the whole pope and antipope story is fascinating), it was filled with details like how many pounds of apples were used for dessert and how much silver was in each fork. I don't usually badmouth tourist attractions, as I know everyone's experience is different, but this was a real lowlight.

I'm in accord with the others' opinion of the Papal Palace. My instinct is to say that if you aren't locked in to the time in Avignon, add it to the days in the countryside. In contrast to that city, the surrounding area is full of memorable places to visit; e.g., Pont du Gard, L'Isle-sur-la-Sorgue, St. Remy. Les Baux, Fontaine de Vaucluse (my favorite), and Carpentras.

I appreciate all the suggestions. From what I can make out I might be better off spending only a half day and evening in Avignon and rent a car for 3 days instead of 2 . Are there plenty of places to see in 3 days within approximately a 100 mile radius of Avignon?

heck yeah, Arles to the south, Gordes to the east

I based in Nimes for several days, visited Avignon, Albi (more interesting, in my opinion), Pont du Gard (you can raft or canoe part of the river), Orange (great restaurant adjoining the Roman amphitheater), Arles - all by public transportation, so with a car you will be able to see even more. Don't discount Nimes!

I enjoyed Arles and enjoyed Nimes even more. I didn't have a car, but with one, there's definitely plenty to do in the area.

Arles has two Roman ampitheatres and a new(ish) art museum as well as a well-regarded outdoor market twice a week; this link includes market info: http://www.arles-guide.com/arles_guide/market_day_in_arles
It can be reached easily by car or train. So can Montpellier, a pleasant stopover. The advantage of going to Orange by car is that you can also drive by the "new" palace of the popes, built as a summer home for the French popes. It is now a pile of rubble on a hill but the famous Chateauneuf du Pape wineries draw tourists. http://en.chateauneuf.com/home
The Orange ampitheatre's famous acoustics aid the annual summer opera festival outdoors, in July and August this year and just about finished.
Avignon also has a famous summer theatre festival, held in July this year with 63 shows and attendance around 167,000. "Alternative" is a weak description of its programs but its formula resembles the Edinburgh Festival Fringe. Kerouac wrote about the festival in this forum several years ago. Obviously such an attraction puts a strain on accommodations so plan well ahead for 2017. http://www.festival-avignon.com/en/

Your decision to spend only 1/2 day in Avignon is a good one. There is so much else to see in the area that is more interesting. I've spent parts of several trips in that area, and found Avignon to be the biggest disappointment. We spent a fair amount of time there in between buses (Avignon is a big bus transit hub), and that was plenty. Nimes, Pont de Gard, Arles, L'isle-sur-la-Sorgue, Saint Remy, and lots of small villages, are all more worthwhile in my opinion.