A non dosage champagne. Cuts through the spice, fat and the sweet pineapple flavor
I like this idea!
“Drink Cheapest Available.” 
Having said that, I think lots of wines could work, just don’t drink anything too precious. I’d be happy to try Zin, a lighter red, or any non-oaky white.
Modelo Ale or really good Margaritas like my wife makes. Not really a fan of wine with tacos. Had tacos al pastor last night as we cook a Mexican meal every week.
Beer. And not a hoppy freak show. Just some nice lager or pils.
my first thought was Albariño from Spain (or Portugal).
I don’ know why my mind went to Italy on this but what about Frappato or a good dryer style Lambrusco served well chilled? The big red fruit, low alcohol, high acid and spritz sound refreshing and delicious here.
Had Spanish garnacha the other night with tacos, not al pastor though. Paired fairly well.
Lots of red blends work really well. They can be the old fashioned CA OV blends or Southern Rhone blends. The real challenge is to get the tacos. Despite where I live it is not easy to find tacos that are in anyway similar to what they are like in the respective parts of MX. In this case Guanajuato.
We usually go with a medium bodied, bright rose with tacos, which always include some pastor, if we do wine at all. More often Jonathan drinks beer and I have a margarita. I have trouble with most red wine and spice in general, and I do want a little sweetness if there’s going to be pineapple in there. I’ve not thought of lambrusco before, but I can see how that would work. I can also see how new world syrah could work, but since I don’t like it very much, it wouldn’t be my choice.
I like a Paloma or beer with tacos usually, maybe a margarita if it’s made well. I do think off-dry Riesling works well though. I tend to go fairly spicy on tacos (prefer Yucateco green or XXX hot sauce for Mexican food) and never find that red wine works with that level of spice.
Beer (lager, pilsner, farmhouse ales - can’t stand IPAs) or Margaritas. Wine with Mexican food has never crossed my mind.
Gosh I hate margaritas
What don’t you like about them?
You have some strong dislikes. I dislike probably 99% of margaritas, but a good margarita is quite nice.
Tequilla
I can see that being a problem.
For red wine, I’ve always enjoyed new world / fruit forward Syrah with Mexican food.
A white with a just a dash of RS. The orange, mango, pineappley hint with some bright fresh acidity really melds well with the salty, savory, spicy, sweet fat of pastor. Champagne works too!!!
Just had a taco al pastor dinner with an 02 auslese. Wine wasn’t the greatest in the world, but the match worked pretty well, so +1 on the off dry Riesling suggestions.