When you cross the bridge onto the island of Flores and look to your left you'll see a building with the top floor a terrible shade of pink. That is where you want to go. It's not fancy, but neither is it expensive or pretentious. All the rooms have two double rooms with private bath and wifi for 80q (about 10us). The place is kept super clean, although in a couple of spots it could use a few new tiles and a new paint job. There is a great little restaurant down stairs with cheap breakfast and good coffee. One thing to watch out for though is that if you order encheladas you will get tostadas... it's a Peten thing. Get the tacos (which are really taquitos) or the huevos rancheros which are what they are supposed to be.
All in all, this is a great hotel with a nice view, a good price, wifi and friendly people. The only negative is on the weekends you get noise off the street.