The airlock scene in Anomaly really stands out for me. Especially because a scene or so before, when Archer is trying to talk to the prisoner, he says, "Please get up." I remember thinking, that's so . . . polite. Then a few minutes later, he's suffocating the guy with this I will F you up look on his face. Love that.
Like also, the scene in Carpenter Street when Archer poltely asks T'Pol to untie Loomis from the chair. At this pont Loomis is probably thinking something like, "yeah, try to bluff me
...BAM!!! Then politely asks T'Pol to tie him up again. Just one of many of my favorite Carpenter Street scenes.
Thing about Archer especially after Anomaly, we know he has gone dark because of the gravity of the mission to find the Xindi, but at his core he is still a gentleman -- whether he is jamming up some prisoner for information or having a heated confab with the Vulcans. It's a weird paradox. Makes him seem rather unpredictable.