Hi
Training is pretty diverse area. Are you thinking primary ( towards a pilot certificate ) or something a bit more advanced. the more info you give the easier to recommend somewhere.
I fly out of Palo Alto and it is pretty busy but the controllers are some of the best and very used to students so are more friendly.
The area is in the heart of silicon valley and so the planes are new and well maintained.( but cost a little more)
my club is West Valley Flying Club
www.wvfc.org
http://www.airnav.com/airport/KPAO will give you more info about the airport
hope this helps