It always seems to me that every recipe tastes exactly the same - no matter what is it.

One thing I've learned over the years using a slow cooker, ALWAYS saute onions and garlic before slow cooking. It's easier if your slow cooker has a saute setting then you can do that first before adding the other ingredients. If you don't, you can get that metallic flavor from them.

Soups, stews, pulled pork, carnitas, ropa vieja, chili, Indian dishes are all good in the slow cooker. DH is from India and frequently makes daal and keema in the slow cooker. They're delicious after simmering low and slow all day. We especially use it in the winter.