The trades for Allen/KG were not out of the box, so much as they were out of left field. Every GM in every sport, managing a middle of the pack team is sitting in a sniper tower, waiting for a moment like that to present itself. DA gets credit, but as far as "out of the box" goes, does not apply.
1. The PP/KG trade however does. He even had to assume that the first two, maybe even three picks were going to be hot garbage at the end of the first. Not one person saw the level of paydirt the organization would hit on that trade. This has to be number one. The team would not be remotely close to where it is now.
2. IT for nothing trade. I honestly would have to look it up. I know it amounted to nothing, and wow did it lead to us landing one of my favorite celtics of the modern era. Sucked to see IT go, but this move also led to the out of the box, trading with the enemy deal that brought us Kyrie Irving.
3. Rondo for cash??? One of DA's biggest draft instinct hits, by far. Every draft analysis said Rondo would/should be a top 10 pick, "if only he could shoot..."
I am extra partial to #3 because I had the pleasure of running in to Steve Kerr (GM of the Suns at the time) at a Padres/Diamondbacks game shortly after we won the finals (I live in SD). I got to walk by him and say "Hey Steve, thanks for Rondo!!!" Had my Celtics hat on. It was wonderful!