I'm personaly very interested in trying Minden and Tahoe in
the Western US. Huge thermals, wave in the winter, and
huge convergence make this a mecca for Western soaring
for me. And the prices at SoarMinden look pretty reasonable
too.

Training somewhere that allows you to use water because there
is so much lift, and probably requires oxygen too, would be
my choice. Probably not as good for beginners
(Avenal, Hobbs, and Tucson have super cheap club type
operations for that, and there are tons of other great
sites here in the western US for just getting a US rating).

http://www.soe.ucsc.edu/~mjboyd/cfi/glider/gliderclubs

was my survey of California, USA gliderports about a year ago.

For my training, I picked a place that was low hassle
(I didn't want umpteen checkout flights), had a variety of
gliders, had cheap and available tows, had cheap rentals,
and had great soaring nearby. Avenal is three hours drive
away, and I'm willing to do that instead of Hollister
(which is significantly more expensive, has less variety
but higher performance gliders, and has infrequent
soaring conditions, but has better instructor
availability - 7 days a week).