In addition to Andrew's point that people have different experiences, it also matters whether you will have a car or not.
Without a car, I found Arles a much nicer city, but Avignon has better transit connections (I did a few nights in each). And I actually preferred Nimes to either one.
If you have a car, you will probably prefer a smaller village, rather than the small cities of Arles or Avignon.
If you want an apartment or house rather than a hotel, you can look at Airbnb, but should also look at VRBO and other sites like Flipkey. Here's Rick's page of tips about apartment rentals: https://www.ricksteves.com/travel-tips/sleeping-eating/find-vacation-rentals
If you asking whether an apartment is better than a hotel, let's just say that this is a very divisive subject. Some people have strong preferences for one or the other, while others use both depending on the circumstances. There are definitely pros and cons to each. However, if all four of you want to share a single accommodation and you don't want two rooms, you will need a house or apartment (unless you really fancy four people sharing one bathroom).