Nice writeup. However, I will say starting with "Deciding who should be in the top 25 was easy" is one of the more ridiculous statements you could've made. There's at least 25 more guys who deserve some sort of consideration.
That said, it wasn't too bad. The only guys I would've definitely left off are Yaz & Rose. And I could quibble about the order (I would've went with Gehrig over Williams & bumped Aaron up a few notches) but that's basically minor.
The huge omissions for me is Bonds. Before the steroid era of his career allegedly began, he was already the only player in baseball history with at least 400 homers and 400 steals and already had a ton of gold gloves.
BTW, you undersold Ty Cobbs in the power department. To make people understand you should've pointed out that he played during the dead ball era when hitting 5 HRs was a big deal. He finished in the top 3 7 times.
Others to consider (some have already been mentioned):
Lefty Grove
Eddie Murray
Cal Ripken Jr.
Mariano Rivera
Bob Gibson
Nolan Ryan
Steve Carlton
Randy Johnson
Pedro Martinez...yes, I know what you're thinking. Many historians rank him as one of the best pitchers ever. If you're not convinced, think about this: he ranks 13th or better all time in WHIP, Winning%, Hits Allowed/9 IP, BB/9 IP, SO/9 IP, Strikeouts, SO/BB and Adjusted ERA+. He's also played through the steroid era, has a career ERA of 2.91 and has never lost more than 10 games in any season. Had he not had arm troubles he'd very likely be really close to 300 wins by now.
Roger Clemens??? I could see leaving him off because of the cloud hanging over many of his accomplishments. He's different from Bonds in that he was borderline at best for the HOF before he allegedly began using roids. Yes, he had 3 Cy Youngs & an MVP but was mediocre by the time he turned 30 & spent his last 4 years in Boston as an average pitcher. He left there at age 33 with less than 200 wins & roughly 2600 strikeouts. He was well liked at the time & had he quit he'd likely be in but the case could be made that he shouldn't. Tacking on his numbers from the time he went to Toronto & you nearly double his win total, add about 2000 strikeouts and an astounding 4 more Cy Youngs.
and my trifecta of catchers: Bench, Yogi Berra & Mike Piazza. Piazza isn't the defensive player the others are but he's more than arguably the best offensive player ever at the position.