Personally I prefer to use the term "work with" over "worship". Worship implies that the deity is seperate and above you and most of us view deity as with in us and all around us, someone that helps us, watches over us, etc.
As for who... that depends. Many Wiccans work with a general idea of deity. Masculine God and Feminine Goddess. Others work with more specific facets of deity such as Greek gods & goddesses or Celtic, or Egyptian etc.
