When I look at the map it seems like there are a lot of lakes east of Fresno. Which ones are good for wakeboarding?

Pine Flat.

Pine Flat-Lots of places to ride and you can usually get good water throughout the day.

I used to go to Pine Flat a lot as a kid. Nice alternative to Millerton. I am not sure there is any type of water sports at Huntington Lake. They have a sailboat regatta every year (windy) and it's pretty pristine, so I would imagine it doesn't allow water sports plus the water COLD year round (it freezes over in winter). Someone posted a pic of riding at Shaver a while ago, but to me the water always seemed cold even in the summer. My cousin said that there is a lot of floating debris at Shaver, as well. But damn it sure is scenic up there.

Shaver is actually a nice lake for boarding and camping (Edison Campgrounds). I went last year for around 4 days and it was great. Water is clean and you've got glass in the morning and evening. It is a little colder but not bad in the middle of summer. The only drawback IMO is there is a lot of rocks you need to watch out for. Melissa's right, scenery is great. Hunnington is above Shaver and way too cold for me.