Nora Kramer
Google
This is one of my favorite hostels I've ever stayed in.
The pool is amazing, the rooms are cheap, and so much is included in the very reasonable cost. There's a full breakfast and they supply rice or pasta for you to cook for other meals, and there's free caporinhas everyday from 7-8, which creates a really fun communal vibe, where people all gather for drinks at the large outdoor dining table introducing themselves and hanging together.
This is a fun hostel without being a party hostel in that people aren't getting wasted playing beer pong or keeping everyone awake all hours, yet there's still a really social vibe. There are also hammocks for snoozing and quiet areas to get work done.
My only complaint is there wasn't hot water but it is so hot in Mexico I didn't really mind.