Redondo Beach in the Federal Way area is one of the easiest entries, no current, moderate depth, a ton of stuff to look at including several boats and a VW bug. It is much better as a night dive, but it is still worth doing as a day dive. There are actually two different dive profiles you can do which will take you to different places so it is great for a two tank dive. Lots of red octos out at night, the occasional spiny lumpsucker, lots of sailfin scuplins, usually at least one GPO in one of the boats, lots of gunnels, lots of cool stuff. Did I mention the easy entry and lots of "stuff" to look at?
Free parking is limited but the pay parking is inexpensive and is near the boat washdown area which is great for rinsing off the gear. There are bathroom facilities and an outside shower in the summer months.
There are several quality dive maps availble of the site including one that I have modified. If you are interested, pm me and I will send it to you.
Tim