Walyunga is my favorite but there is still no guide. Very pretty area.
Pipelines has the most problems and they are pretty close together but it’s a bit of a hike in.
Boulder Rock is good and has an easy approach.
Millars has a bit of a drive and a bush bash.
Kalamunda and Dreaded are good but problems are spread out all over the place.
Haven’t been to Mt Cooke, El Dorado (still waiting for a mini-guide), Dead Goat (ditto), Wombat Rocks etc etc…
I reckon Boulder Rock if you don’t have all day and if you do Pipelines. Try them first, then the other ones.