The cheap, under $50 Chinese hand pumps found on ebay or Amazon seem to have decent reviews on airgun forums. Rebuild kits (o-rings) are available as well. Keep it lubed and don't pump too fast.
I have a Benjamin hand pump that was included with a used Discovery rifle that works well. It's probably no better than the cheap ones. It's probably a good idea to have a desiccant cartridge installed to remove water but I don't have one. Mine is just used to top off guns if my 4500psi tank is running low.
