Cirrus - to take a cue from your comment in the City Discussions thread about importing a "block of normal Parisian apartments," I was almost going to try to find something similar. Your example from Arlington, VA is probably better than anything I could find myself. If CO Springs gets one, then can Denver have five of those please? It reminds me a bit of a modern version of "The Arconia" (aka the Belnord) from "Only Murders in the Building."
Perhaps more in keeping with the intent of the thread though, I'd probably steal a current one and choose The Post from Rotterdam, NL
I love the way it plays with the rectangular form of the building, but infuses it with both timeless elements (arches) and playful ones. And Denver's blue sky would look
fantastic through those corner balcconies. It reminds me of the formalism of Republic Plaza but combined with the modern playfulness of the Populus hotel.
Since The Post is also a renovation of a historic structure, I suppose I should choose a historic Denver building for it to arise from. I choose the Paramount Theater. Plus, then it would be only two blocks away from Republic Plaza and would make for a fun juxtaposition. At 155 Meters (~508 feet), it is about 2/3 the height of Republic Plaza.