No you can't. If you want to use "favorite" (in any context) you need to say your favorite...<i>something</i>. You could say that they are your favorite people in the world. They are your family and your favorite relatives, but you can't say that they are your favorite.
All the best,
LEARN ENGLISH BY USING IT: ANSWERS & MOTIVATION FOR ANY ENGLISH LEARNER
Student or Learner