In no particular order
Batman & Gordon arrive at the Bat Signal to find Selina holding Kenzie captive at gunpoint.
We've barely seen Batman, Gordon, & Catwoman all on screen together, so already I was hooked. The voicemail was eerie, and the knowing look Batman gives Selina when Gordon says "my god, he's choking her" is so chilling and pitch-perfectly captured by the actors. And to tip it off, Selina's 'nine lives' joke and the reveal of yet another Batman gadget as he scales down the building after her. Beautiful.
Opening narration & reintroduction to The Batman
The opening montage with Bruce's narration felt, excuse the cliché, like the comic book come to life. "The element," "I am the shadows," etc. All just felt really good as a Batman fan. The brutality of him subduing the gang attacking the bystander followed by his motorcycle ride through Gotham City (beautifully designed by Matt Reeves & the team) and finally the introduction of the Bat Cave and Bruce's contact lenses and war journal. All really awesome and a great way to start the proceedings.
Batman and Gordon investigating the crime scene at the Mayor's apartment
Our first real taste at a detective Batman. Loved the way Pattinson channeled a shaman in his silent, stoic portrayal of Batman (I forget the interview where Reeves revealed this) -- Batman is in a brightly lit room for this encounter, his element of fear is non-existent so he instead hyper-focuses on the crime scene at hand, barely noticing the cops around him. His powers of detection almost mythical...