If you want good breakfast in Harlingen or Brownsville, head over to Chapitas. Best breakfast in Harlingen, period
My wife and I have been to the Rio Grande valley many times and we always make it a point to stop at Chapitas for breakfast, either coming from or going to McAllen, TX. The portions they give you are copious, the food is authentic and the prices are very reasonable.
The tortillas are home-made, the eggs are great and the pancakes are enormous. You will walk out of Chapitas fat and happy.
The location is a little out of the way. It's just east of where Hwy 77 intersects with Hwy 83, just west of the airport, on the north sunshine strip. It is worth the trip, my friends.