Depends, but I think I hate the fly out. A fly is going to be out except for the most exteme circumstances. On the other hand, a lot of singles are just ground outs that didn't go to where the fielder was. Of course, the GIDP is the worst, I'd rather they hit it in the air when the situation calls for it. The absolute worst is the first pitch out of the strike zone foul pop out. Oh man, that last part is gospel. ESPECIALLY if there are guys on base and in scoring position. And the team is down by a run or it's tied. And the guy that pops it up is normally a sure bat. That's instant ulcer right there. And with ground outs, when I say I hate those most, I mean the pathetic little dribblers that are barely more than a bun that give the infielders plenty of time to set up and throw. We've been seeing a TON of those lately...apparently when people were talking about how Pierre would "inspire" the other players with his hard work, they also meant that everyone would copy his weak ground outs, too.