Is Versaille on a Sunday still a bad idea if it is the first Sunday since many museums are free and crowds may stay more in Paris? My choice is Versailles on Sunday or Saturday and then other museums on the other day (except we are visiting the Louvre Friday evening).
Emily Versailles will be very busy on Sunday, free sunday or not.. it just will be. In fact if you are going in season, June-Sept its just going to be busy every day really,, but weekends are busiest because of fountain show . I would choose not to go on a weekend,, and I have gone often.
I think you are wondering if people will stay in Paris because they can go to other museums free, thus keeping the crowds down in Versailles because you would have to pay there. If it's peak season - it will be crowded anyways. If you are going in winter, when Versailles is free on the first Sunday, I found it to be a great time to go. Yes, it's crowded. But because you don't need tickets to get in, the line moves really quickly and you don't really wait at all.
We will be in Paris 7/5-7/9 and we can't go on Monday. Do you suggest going to Versailles on Saturday or Sunday or should we skip it due to the crowds?
I suggest you go early. Be the first in line so to speak, and avoid the crowds that way. Some have also reported good success with going through the palace late in the day, after most of the tour busses have left. The gardens will be crowded on fountain show days and it costs an extra 8 euro to enter the formal gardens. But the gardens are HUGE, crowds there won't be a significant problem and mostly crowd around whichever fountain is turned on (they operate intermittently - not all at once). Even on fountain days, it's easy to explore quiet spots in the groves with almost no one around. Don't skip Versailles just because it might be crowded - just about every major tourist attraction in Paris will be crowded that time of year...
I vote yes on going to Versailles. I would go early, but do the gardens and the grounds first. Then, later in the day, I would tour inside the palace when it's not as crowded. Renting bikes down by the Grand Canal is a very fun way to see everything.
From the Chateau Versailles web site: The first Sunday of months from November to March, admission is free for tours So no worries about free sunday for you, but it will be very crowded regardless. We went recently, were in line by 8:40, and were packed like sardines. It was somewhat better when we re-toured the rooms around 3:00. I agree with the suggestion to cover the grounds first, and rent bicycles. It is a beautiful place to spend the day.