Here's a deal that should, in my mind, have made the cut:

In 1992, the Cincinnati Reds traded Paul O'Neill to the New York Yankees for Roberto Kelly

Let's take a look at how the two stack up, following the trade:

Paul O'Neill - .303/.380/.492, 720 R, 185 HR, 858 RBI, 80 SB, 4 WS
Roberto Kelly - .298/.337/.446, 367 R, 68 HR, 237 RBI, 84 SB, 0 WS

So... O'Neill gave the Yankees wonderful production from 1993 to 2001. Kelly gave the Reds all of 78 games, then had a middling career until retiring midway through the 2000 season.