I agree with Nathanael about US and Norco. KYB isn't bad either. I use a superb German-made bottle jack, but got it for an equipment review (i.e. free). It's bloody expensive.
Actually, a very fine jack that you can frequently pick up used on eBay is the Land Rover double-extension bottle jack that came with a U-shaped top to cradle a beam axle. They were made in Italy.
I'm about to test some interesting bottle-jack accessories - extensions, a large base plate, etc. - from Bogert Engineering, who made the Safe Jack I reviewed some time back on OT&T.