Hi, Katie!
Both of these Mexican restaurants are amazing! I love the atmosphere of San Angel Inn, but also enjoy the views of World Showcase Lagoon from La Hacienda. I think the menu has more choices at San Angel Inn, but the choice is up to you! I suggest you click
HERE to see the different restaurants. Click on each restaurant to take a peek at their menus to see what you might enjoy more.
Regardless of when you go, I highly recommend dining reservations for all the parks. Even if it is last minute, get a table reserved. You do not want to wait until everyone is hungry to then try to get a table. It is nice to start your day knowing exactly where and when you will be having lunch and/or dinner. It is also a good way to gather the family back together if you head off in a few directions in the parks.
If you have a smart phone, download the free My Disney Experience app. It is so helpful with wait times, park hours, and you can even make your dining reservations. I was amazed by all you do on this app. Give it a try! You will really like it for reserving that last minute dining time!
Have a great time dining in Mexico. You are really going to enjoy it!