this is a fascinating subject to consider, in my opinion...while the Jewish people were identified as "chosen" and individuals such as david, as have been mentioned previously, were especially close to God's heart, we were all made in the image of our Creator...God loves humankind with a perfect love and i dont believe we can even partially wrap our human understanding around that concept...man as a creation was His "favorite" among all His many works but among them, i cannot believe he loves any of us more or less than another...
although, if you mean "favorite" as some one or group that is, for whatever reason, more pleasing to God, i think that's a completely different discussion and much more difficult to answer...the Scripture seems to indicate that to be correct, though, in my understanding...maybe as an inspiration for us all to aspire to reach that point? i dunno...