Congratulations to Jim Thome on his 600th home run. He joins an elite group of ball players who've hit that many. However, what was once a near-unreachable number seems less impressive these days since 5 of the 8 players on the list all got there in the past 10 years, while there were only 3 players to ever hit 600 HR's in the first 100+ years of professional baseball.
So here's my assessment of the members of the club:
1. Babe Ruth. You can't even argue this one as the Babe was the best player ever. His numbers: 714 (HR's) in 8399 (at-bats) equals 1 HR every 11.7 at-bats. In addition to HR's he also managed to hit .342 overall.
2. Hank Aaron. Although he hit more total homers than the Babe his numbers are: 755/12364/13.3. His career BA was .305.
3. Willie Mays Hard to rank Mays behind anyone overall (except maybe Ruth) because of his skills on the field and on the base paths but his HR numbers are: 10881/660/16.5. His career BA was .302. Although Mays had the highest number of at-bats per HR on the whole list, keep in mind he played 12 years at Candlestick where his left field power was blocked by the wind and he had to go to right field with the ball. It's hard to imagine how many HR's he'd have hit if he were able to pull the ball down the left field line.
4. Ken Griffey Jr. While his numbers 9801/630/15.5, BA of .284 fall behind some of the others, Griffey missed a lot of time during some of his best years due to injuries and some of those injuries are because he played so hard he'd end up crashing into fences. Had Griffey played the full seasons in 2002-2004 he probably would've ended up with more HR's than Mays. Plus in the steroid era Griffey is widely accepted as having played clean (those injuries may've been avoided or healed earlier if he had used steroids).
5. Barry Bonds. Here's where it gets really debatable. Bonds clearly padded his HR numbers with steroids (see below on A-Rod and Sosa). I rank him above a couple of the others for this reason: I think he'd rank here even without the steroids. Bonds numbers were: 762/9847/12.9 and his career BA was .298. All these numbers are exaggerated by steroid use but Bonds already had the following numbers by 1998: 6621/411/16.1(It's widely accepted that he began using steroids after 1998 when he had numbers worthy of an MVP but all the attention went to McGwire and Sosa) and was then averaging 31 HR's per season. At that pace he would've exceeded 600 even without the steroids.
6. Alex Rodriguez. Again a steroid user, but another player who likely would've made it to 600 without the juice. Hard to compare his numbers pre-post steroids as it's unclear when he began (I think he admitted to usage in 2003 only). His numbers are 9131/626/14.5 with a .302 career BA. It's his BA that really puts him ahead of ...
7. Jim Thome. Another clean player in the steroid era, who has quietly amassed 600 HR's over the past 20 seasons (all but 10 of which were hit from 1994 onward). Thome's HR's per at bat are up there with Aaron: 8167/600/13.6 but those numbers aren't enough to rank him higher mainly because Thome always swung to hit homers. His career BA is .277 (below every player listed so far) and his strikeouts far exceed anyone above him (he strikes out once every 3.3 at-bats).
8. Sammy Sosa. What can you say about Sosa, his inclusion on this list is a direct result of steroid usage. Without steroids he'd probably not have even hit 500 HR's. He also struck out more than Thome, averaging one K per 3.8 at bats.
Thus the 600 HR club includes 3 of the all time greatest, 3 more who probably would be in that category if they'd played clean and stayed healthy, 1 great power hitter and 1 guy who has no business being admitted to the club.