Mexican beers get a bad rap in the US amongst experienced beer drinkers, underservedly, perhaps, but largely the fault of the beer producers. They basically export mostly the bad stuff which, ironically, is how you make maximum profit in the US (see BMC). The Mexican beer brewing tradition started with the French and especially the Germans. They brought lagering to Mexico by buring chambers in hillsides and brought the tradition of Vienna lagers as well as pilseners. It's not surprising that they wound up also brewing with local ingredients, corn, which resulted in the Sol/Tecate/Corona branch.
I think Negra Modelo and Dos Equis are quite drinkable. From around Sept/Oct until December Noche Buena is available, which is a bock style beer ~7% IIRC. It's a very nice beer. There are plenty of others that you probably won't see unless you're in Mexico or very close to the border.
In terms of ales, you just don't see them unless you are in a particular city that happens to have an adventurous microbrewery. There are several successful ones, but in Guadalajara where I most frequently go they usually fail within a year. I think it's primarily marketing, but who knows. The Mexican craft beer movement seems to be ~25 years behind the US so it'll be a while I suspect before we abroad see much activity.
But the Mexicans learned beer making from the best, and some of the brewers still have a German or Czech influence in the form of a brewmaster or business interest, so there is potential there.
...a couple of those and you don't need cervesa!
Rolling Rock in a can is the most offensive beer ever IMO. Corona is few steps up.
