Sure, there are quite a few ticky-tacky tourist shops, but folks still get around by golf cart and the crushed-coral beaches are undeniably lovely. As for the calm turquoise water of Isla Mujeres, well, you really just have to see it for yourself.
Come sunset, there are plenty of dining options, and the nightlife scene moves at a carefree pace.
Some people plan their vacation around Cancún and pencil in Isla Mujeres as a side trip, but the island is truly a destination in its own right, and a surprisingly affordable one at that.