Answer:
At the end of the 2007 season, the all-time home-run leaders were:
1. Barry Bonds (762)
2. Hank Aaron (755)
3. Babe Ruth (714)
4. Willie Mays (660)
5. Sammy Sosa (609)
6. Ken Griffey Jr. (593)
7. Frank Robinson (586)
8. Mark McGwire (583)
9. Harmon Killebrew (573)
10. Rafael Palmeiro (569)