http://www.leatherique.com/
The best I have used is Rejuvenator Oil by
www.leatherique.com
They have a terrible website! But it is by far the best leather treatment you can buy. They are also very well known for their dye kits to restore old worn leather to like new color and condition. It is the official leather care of the Rolls-Royce owners club (I wish I could be a member!). As well as a favored product of Ferrari, BMW, MB, etc. auto clubs and specialty restoration shops.
DO NOT under any circumstances use armor all or similar protectant on your leather!!!!! This will seal the pores and do much more harm than good!
If you want to find something local, Lexol is probably the best stuff you can commonly find in stores. It is nowhere near as good as Rejuvenator Oil but does condition well without harming the leather.