In my humble opinion, two classic stories came out of Phil Jimenez's run:
Wonder Woman #170: "A Day in the Life" co-written with Joe Kelly: To this day, many comic book fans, at least on social media, mention this story when they talk about how they imagine not only what Wonder Woman's day-to-day looks like, how she puts her skills for science and diplomacy to work, but also regard it as the blueprint for how to do this genre of story. At the time that it came out, some Wonder Woman fans were snarky about this or that in regard to the details, but I think the story has, for the most part, stood the test of time.
Wonder Woman #172: "Her Daughter's Mother" (featuring the death of Hippolyta): Our Worlds at War was a most disjointed and ridiculous event that didn't make a ton of sense as the writers didn't communicate important details about the nature of it. But in Jimenez's issue, he tied together and clarified so much, and shocked people by making the Wonder Woman tie-in the very best issue of what was supposed to be a Superman event. That death scene with Hippolyta, showing the true ravages of war, still haunts.