My current favorite is salsa chicken because it takes a lot of effort out of prepping.
There’s various recipes for it online, but I basically just toss a big tray of chicken and a jar of salsa into the slow cooker. Then season with roughly 1 tablespoon per pound. So like 5 lbs of chicken might be 3 tablespoons of a seasoned salt and 2 tablespoons of cumin. Mix it to coat and cook for 4-ish hours on high or 6-ish on low. Once it temps 165 you can chop it, shred it, pull out whole pieces, etc.
From there the sky is the limit. Throw it on baked potatoes, eat it straight up with freezer bags of veggies, make sandwiches/tacos, add some stock and veggies to make soup. Just really versatile, very easy to track protein from, and certainly beats eating boiled dried out chicken breast several days later.