One of the best best parts of the PCT is through the Trinity Alps. If given enough time along this section of trail you could visit more than twenty lakes along this stretch of the Pacific Crest Trail.
Going from north to south you should spend your first night at Upper South Fork Lake.
From here you could day hike to Hidden lake or go off trail to Bucks Lake.
The next day you could set up camp at Fox Creek or Mavis Lake and spend the afternoon exploring the basin and trying to find Virginia and Section Line Lakes. The next night or two should be spent at Telephone Lake. This is a good base camp for day hiking West Boulder, Middle Boulder, and a few other small lakes.
Around here you will start to notice a change in the geology. The old broken down granite will start to give way to a red volcanic rock. And with this change the doug firs give way to sugar pines.
Next is the highlight of your trip East Boulder Lake is the second largest lake in the Trinity Alps Wilderness. This is where you should spend the rest of you trip.
The fishing is great along the whole trip but at Upper Boulder Lake you can catch some of the largest fish I've seen in the Trinity Alps. Also the day hiking from East Boulder is endless. There are over ten lakes that can be reached in just one day.