We've all made mistakes, none of us are invincible. Some of us get wasted and for some reason operate fantasy baseball teams while drunk. Post the most regrettable trade you've made, what year it was, and what part of the season it was in. Or post a regrettable drop you made, like dropping Fielder in April of '07, or a blatantly bad draft pick, like Harden in the 6th round. Mine was:
This was last year, about 2 weeks into the season when A-Rod already had like 10 home runs. I have NO idea what I was thinking, but I was unaware of Oswalt's and Konerko's impending crappiness. Still, even at the time I got crushed in that trade.
And it doesn't count if you traded for a player with legitimate expectations but wound up disappointing. I'm talking about trades and moves where, 5 seconds later, you were frantically scrambling for an "undo" button.