In episode one, four members of the team rob the entire NPC student body blind by holding a rock concert. Angel tried to intervene, and the entire team absolutely unloads all of their ammunition on her. That would be awesome enough for episode one, but the true awesome part? It only manages to slow her down.
As of Episode 11, Angel now has freaking WINGS. As decoration (see below).
Yuri winning a one-on-one fight against one of Tenshi's clones on episode 8.
Yuri: Just give it up. My next knife here's going to take care of your throat.
When Otonashi died in the real world, he gave a particularly awesome showing of keeping a half dozen people alive despite serous injuries and few resources to work with. He tops it by becoming an organ donor, just to able to help a few more people.
Episode 11 has EVERYONE(except Ooyama, Fujimaki and Takamatsu) being a badass in the first open battle against the Shadows.
And in episode 12, Yuri destroying the computers that are creating the shadows.
Special Mention goes to the fight with the shadows near the beginning of the episode which included TK spin fighting down a rail shooting shadows, Ooyama sniping shadows, and a skinny Matsushita and Otanashi talking while offhandedly shooting and punching the approaching shadows.
From the light novel / manga: Angel vs. Shiina.
The plan that Yuri came up with to defeat Shiina while she was busy with Angel, ending with pushing Hinata off the roof so he could land the final blow on her. Like many of Yuri's plans, it was just crazy enough to work.