2002 He-Man's first appearnce in the show. From coming out of nowhere to save Teela, to singlehandedly beating Skeletor's top generals (using nothing but a giant rock), to going toe to toe with Skeletor.
From the premiere of the 200x series' second season, "The Last Stand" from the 2002 series, He-Man fights against all of Skeletor's Evil Warriors and the Council of Evil - beating a lot of them silly despite being outnumbered. The tide does turn against him, but by then, he's held out long enough for reinforcements to arrive.
Even before he transforms and faces the villains as just Prince Adam to delay them as long as possible.
In "Second Skin," Orko tries to interrogate the captured General Rattlor about King Hiss's latest plan. Rattlor won't answer any questions and even threatens his interrogator. Ultimately, Orko whips out a mongoose, makes it grow with his magic and lets it try to break into Rattlor's cell.
"Keep it away! I'll talk! I'll talk!"
In "History," Tung Lashor unknowingly interrupts a By the Power of Grayskull! moment and tries to eat Adam. Cringer responds by biting down on the Snake Man and sending him flying into the brush.
He-Man's battle against King Hiss and Rattlor on a river of flowing lava.
He-Man destroying the Well of Darkness in front Evil-Lyn and Count Marzo, thus keeping Hordak imprisoned.
Even Mekaneck got a chance to be Bad Ass in the 200x series. In the episode "Mekaneck's Lament" he got the chance to save the whole kingdom from Count Marzo, even gaining an impressive Arch-Enemy in the process.