Bars

Casa Mayor- Owned by Ricardo and Natalie, with roots in the organic coffee mountain area of Pluma Hidalgo where they own a finca, this upstairs restaurant/bar is one of the favorites of locals on the Crucecita Plaza. Most nights have live music with someone on guitar, and the open air ambiance overlooking the square is great. Check out their website for info on their ecological tours in the mountains around their El Pacifico finca. Though the website is in Spanish, Ricardo is fluent in English if you contact him through it.

La Crema- La Crema has an upstairs location on the NW corner of the main plaza in Crucecita, and has a comfy and funky blend of couches, easy chairs, and high chairs, along with colorful hangings and huge candles. Some of the best pizza in town, made in a wood-fired brick pizza oven. Atrociously slow times for turning out pizza when they're really busy, though. Most of the staff is fluent in English. Also has a cool store inside that sells the same kind of colorful things the place is decorated in.

Restaurants
There are more good restaurants than bad ones in La Crucecita, and it's really hard to go wrong anywhere around the main square. All up and down the side streets of Crucecita are simple places the locals patronize, from taco stands to full menu restaurants, and most of them tend to be very cheap and decent. Just look for a total absence of frills and plenty of customers and you'll know you're at a good spot. For other than standard Oaxacan cuisine, the restaurants singled out below are local classics.
Giordana's Trattoria - For great value on incredible Italian food, this small restaurant is a local favorite. Giordana is one of the warmest people in Huatulco, and makes authentic Italian like no other. At the corner of Gardenia and Palma Real in Crucecita.
Cafe Juanita- On the west side of the park in Santa Cruz, Canadian Jane Bauer runs this small upstairs cafe that serves a variety of innovative dishes, with a different limited menu every night. The food is outstanding in an intimate setting, and Jane also offers cooking classes through her Chiles and Chocolates cooking school.
Mediterraneo- Franco, the Italian owner of Mamma Mia's in Crucecita, opened this beach location in Santa Cruz in late 2013. It has been a tremendously popular addition to the beach, which has otherwise consisted of the usual overpriced and average beach seafood restaurants. He often has live music, comfortable seating on the sand, and a traditional wood fired brick pizza oven.
Terracotta- Housed in the elegant Mision de Los Arcos hotel on Calle Gardenia a half block off the main square in La Crucecita, Terracotta is a beautiful, air-conditioned restaurant with surprisingly reasonable prices. Service is pleasant and fast, and the Oaxacan specialties are good. It is a dependable, safe place to eat, but the sterility isn't for everyone. For those looking for a more typical open air Mexican dining experience, you might want to try elsewhere, but for those looking for quiet and air conditioning and cleanliness, it's a good choice. Also has an outdoor cafe with free wireless internet, and is a very popular breakfast spot.
Itoo- A new restaurant two blocks to the west of the park in Santa Cruz, this is quickly becoming a favorite breakfast spot in Santa Cruz, with enormous pancakes (don't order more than one unless you're hungry!) and a good lunch and dinner menu in an elegant setting.