For me, the early seasons of 'Criminal Minds' really hang together because of Gideon’s steady hand — he’s essentially the lead profiler for almost every case in season 1 and throughout season 2. He opens the show in the pilot, 'Extreme Aggressor', and his methodology and moral gravity shape how the BAU approaches investigations in those episodes. That meant that in practice, any episode from the first two seasons that features the team’s behavioral analysis has Gideon steering the profiling work, mentoring teammates and taking the primary role during briefings and interviews.
He stays the central intellectual force into season 3 until his mid-season departure, so if you want to see Gideon in full leadership mode, binge the bulk of seasons 1 and 2 first. What I love about revisiting those episodes is how his calm interrogation style and quiet ethics contrast with the show’s later, punchier leadership dynamics — it makes the early seasons feel like a different, more cerebral animal. It’s bittersweet to watch him walk away, but those episodes really knit the early series together, and they remain some of my favorites to rewatch.