There's been some criticism of this list because the three (two plus an "honorable mention") HR listed so far weren't "meaningful" in terms of winning important games, or in pennant races or the postseason.
That wasn't the only point of doing this list, although as the list goes on, you'll see HR like that on it. I also wanted to note certain HR that were memorable (Ryne Sandberg's blast that didn't officially count on 8/8/88 was certainly memorable), or in terms of the Lou Brock HR, that were historic (Brock's HR being one of only three that were hit into the CF bleachers at the Polo Grounds in New York, and that HR, as I wrote, might have been one of the reasons that Brock was pushed even harder to become a power hitter, hastening his eventual departure from the Cubs).
Anyway, let's move on to a home run that was both memorable and important in terms of winning a game for the Cubs that had been hyped, far more than a regular season game usually is -- a Saturday afternoon Cubs-Yankees game, the second of the first Cubs-Yankees interleague series, and a pitching matchup between Roger Clemens and Kerry Wood. Rumors flew before this game that scalpers were getting as much as $1500 for what, at the time, was a top-priced $45 box seat ticket. I talked to at least one Yankee fan who had driven in from New York for the series and who had paid $500 for what was, at the time, a $20 bleacher ticket. Here's what I wrote about the game at the time on my old blog.
Both Wood and Clemens threw well -- they allowed three hits each, though Wood outdid Clemens in the strikeout category (11 K's for Wood, 5 for Clemens). In the fourth inning, Jason Giambi hit a popup to the middle of the infield, and Wood and Hee Seop Choi had a scary collision going for the ball; Choi fell to the ground, briefly motionless as an ambulance drove onto the field from the right-field gate. Amazingly, he held on to the ball for the out. Choi missed most of the rest of June with a concussion and was never really the same player when he returned -- from June 30 to the end of 2003 he hit .164/.263/.269 and after the season was traded to the Marlins for Derrek Lee, one of Jim Hendry's best trades.
Oddly, this tough break for Choi wound up providing the memorable HR moment and winning the game for the Cubs, because Choi's replacement, Eric Karros, came up with one out and two runners on base in the seventh inning and the Cubs trailing 1-0 on a Hideki Matsui HR. Joe Torre came out and yanked Clemens, who had thrown only 84 pitches (Wood, in 7.2 innings that day, was allowed to throw 120 by Dusty Baker). Torre called for Juan Acevedo to face Karros, who had saved five games for the Yankees in April in Mariano Rivera's absence, but who had, since being relegated to setup duty, been awful (in 12 games from April 30, when Rivera returned, through June 1, he had allowed 17 hits and 9 walks in 13 innings and had a 9.69 ERA).
Karros was ready. He smacked Acevedo's first pitch into the LF bleachers for a 3-1 Cub lead; the Cubs tacked on two more in the 8th and won the game 5-2. Torre also used Acevedo the next day against the Cubs; again he threw poorly, and two days later the Yankees released him.
Karros' HR and the Cub win that day, in front of a packed, rocking house, moved the club record to 33-27 and kept them only one game behind the then division-leading Astros. It was the first of a four-game winning streak and one of the signature moments of the 2003 season, and one that cemented Karros' place in Cub lore forever.