Depends on your ability level! I had some fun scrambling to the top of Wotan's Throne in June while at TC, but you need to be comfortable with some route finding, Class 2 (mostly, some Class 3) rock scrambling, etc. It had some wonderful views of Muir, The Needles, Whitney, and Pinnacle Ridge. You might also try the Meysan Lakes trail before you head up the Main Trail. Cool views of Lone Pine Peak, and a different perspective back down to the Owen's Valley. Can't speak to the Crabtree Lakes yet: I'm heading there mid-August.
Have fun!
-L
