In reply to speedymushmouse:
To avoid the queues on Half Dome tourist route, aim top be there late in the day. I got to the base of the cables at about 5pm, long after most people had gone. There were no more than half a dozen others on the summit. Of course you'll need a head torch, as it gets dark around 6.30 in September - but at least there's less chance of afternoon thunderstorms.
Superb views from Clouds Rest, it's very busy but no permits needed yet as far as I know.
Much better would be Cathedral Peak (up at Tuolumne) fantastic pointy summit, with a tricky scramble to get there (the last section is graded 4, but is around Diff).
But as Offwidth says - The place is one big view, just explore.