The neighborhood stuff is... boring. I only do it because it's something I can do whenever I have a free hour in my day, early morning, afternoon, evening, without having to go anywhere.
Friday mornings for me are never busy work wise so I can always make it out and the park I go to, Great Falls, is notoriously swamped with people, but 7am on a friday I hardly see anymore and it's a good variety.
My Saturday/Sunday spots are almost all wooded with 1 or 2 scenic overlooks and not crowded at all. The trails are active enough they aren't over grown, but spare enough that you don't have to move over for others too often. Part of the trail is used by a nearby horse ranch, so there is some dodging of horse droppings, but not enough to be a real nuisance.
Mainly, I like the variety, 4 days of sidewalks/streets, 2 days of woods, 1 day of rocks. Plus I crush podcasts at 1.5x.
I need to add some core workouts though. Anyone got any good suggestions?