Soaring sites near Pasadena, CA?

I'm going to be in Pasadena later this month on business and would like
to take a day off to fly. I've poked around the SSA and Region 12 sites
a bit and it seems like there are a number of options within a 1.5 hour
(or so) drive.

Before I start contacting all of 'em, does anyone here have personal
recommendations for sites that'll rent a decent glider to a visiting
pilot for the day (probably a Friday)? Are there some sites that are
much better this time of year?

Thanks!

Jeremy