Jeff Day makes a good point about how you define "worst.'' I'm going with a slightly different interpretation with my pick: Timberwolves miscreant JR Rider. He wasn't a terrible player, but he was perhaps the worst human being ever drafted by a Twin Cities franchise.
His rap sheet includes arrests for assault, kidnapping, drug possession and fraud. He didn't show up for an event at a sports bar at the Mall of America; when they complained, he went there and kicked the pregnant manager. When a Pioneer Press reporter asked him about a bad shooting performance, Rider said, 'I know guys who can take you out.'
He was a headache for the Wolves right from the start, showing up hours late for his first practice. That nearly led to an old-guy fistfight between Wolves GM Jack McCloskey and Sid; while we were all waiting for Rider to show, Sid kept yelling, 'I told you you should have picked Calbert Cheaney!'