My favorite taco is leftover medium rare NY steak, thinly sliced and nuked (maybe 1/2 cup at a time) for 15 seconds, plus red cabbage slaw made with sliced red cabbage in a sour cream, lime, cilantro and chipotle (in adobo - to taste) dressing in a warm corn tortilla. The add-ons are endless (cheese, grilled/raw onions, thinly sliced radishes, avocado etc.) and it is always so good!

oops I forgot to point you to my favorite beef soft taco recipe. This recipe used marinated steak, and the steak is folded into a tortilla with some mild cheese and a grilled medium hot pepper. Don't forget the pickled onions, they rock.
http://www.globalgourmet.com/food/special/meat/nogales.html

Hi, use foodpickle when you have an emergency cooking question or need tips in real time. Use recipe databases to look up recipes. That is too general a question, there are so many ways to make tacos, depending on the protein you use. The host here, food52.com, has some member recipes listed here:
http://www.food52.com/recipes/search?recipe_search=taco