I'm a big fan of the tacos from Los Ocampo in the Midtown Global Market. (Service can be flaky, but the food is so good I don't care.) They also have a stand-alone restaurant somewhere, but I haven't been there yet.
Taqueria Los Ocampo
Midtown Global Market
In St. Paul, try El Burrito Mercado - it's a large grocery store with a cafeteria. I recommend carnitas or birria for the tacos.
Or go to El Mercado Central for tacos from La Hacienda and others. (La H also has a stand-alone restaurant on Lake Street.)
1515 E. Lake St., Minneapolis
Actually, most of the taquerias on Lake Street are good-to-great. I went to La Poblanita last weekend and had some nice tinga tacos. (However, I thought their horchata was too sweet.) And they make their own tortillas, which is great!
1617 E Lake St, Minneapolis
City Pages did a Lake-Street taqueria review several years ago, but I think most of the information is still valid (other than some address changes - the stand-alone La Hacienda moved across the street, and the 21xx outpost of Pineda Tacos has been torn down).
After you try some tacos, do please report back on whether you liked them!