As of August 2015, some good pickled jalapeño brands are La Costeña, La Morena and Melissa's. All average at least 4.5 stars on Amazon.com's five-star user rating scale.
La Costena offers jalapeño peppers pickled in vinegar with onions and carrot slices. Reviews say the peppers are not too hot, nor are they mild, and that they have a good flavor. One reviewer suggests that the jalapeños should be crisper.
La Morena's sliced pickled jalapeño peppers are hand-picked in Mexico and are sliced lengthwise rather than into rings. One commentator states they combine well with beans.
Melissa's packages pickled jalapeños in jars. Reviews mention that the peppers are very large and hot.