Which National Parks are best for a day trip out of inner city Perth?

We went to Walyunga NP (north of Perth) a few years ago and it was really nice and green with water flowing from winter rains. There is a huge green grassed area for picnics, kids can run around and play. The best thing was that if you stay till later in the afternoon the kangaroos suddenly appear and they are happy to feed quite close to people. We went for a walk on the short (and easy) tracks near the river and they were just right near us on the ridge near the trail. It was actually a real chance to see them just doing what they do naturally. Later, in the carpark the 28s (parrots) came and hung down really low on the tree branches as if they were just trying to see what we were doing. If you are into birds and wildlife eit would be great day out. I think you can camp there too, but with prior permission.