This is such a hard choice. Assuming you could have only one of these objects (and their associated power set and accessories) I might have to take the sonic screwdriver. The Wizard staff is very tempting though. I'd like the wand :p
The Enrichment Center reminds you that the Weighted Companion Cube will never threaten to stay you and, in fact, cannot speak. In the event that the Weighted Companion Cube does speak, the Enrichment Center urges you to disregard its advice.