Where have you stayed when you go?
Just about always stay on Playa Norte/North Beach. Would always recommend staying there if the budget allows for it, and if you want to be on the beach.
Almost always stay at Nauti Beach Condos, great location, good pool, well cared for rooms, most of which are two bedrooms, so good for families. As the name indicates, they are individually owned condos, so the rooms are all slightly differently appointed based on the taste of the owners. But it still feels like a hotel in terms of services and what not.
Also have stayed at Ixchel Beach Hotel, which is essentially right next door, I'd say comparable or slightly nicer pools, similar level of service and comparable quality of rooms, not 5 star luxury but also not run down discount either.
We are not all inclusive people and I don't think all inclusive is the best way to experience Isla Mujeres. However, if that's your thing, the main two options are Mia Reef - that one that looks like it's own island connected by a foot bridge - and Privileges Aluxes which is among the fanciest/most expensive options. Don't know too much about these places.
Lotus Beach Hotel is probably another one to look at that is an example of the advancement in Isla Mujeres tourism, that location used to be a pretty rustic hotel, now it looks pretty fancy.
I think Isla Mujeres is perfect for people whose idea of a beach vacation consists of a great beach, a nice pool, great beach bars, great restaurants, interesting shops and all of it easily walkable without having to rent or taxi anywhere if you don't feel. There's also a handful of one off "excursion" type things like renting a golf cart, scuba/snorkeling, and things like that, but generally not a ton of stuff "to do" other than relax.
Hope some of that helps.
