Typically, for large air transport aircraft you get just enough hydraulics to keep the aircraft flying. They'll give you roll control through a selected few of the available spoilers and pitch through the stab trim. Emergency braking too - Gear extensions is by free-fall. Emergency electrics may run from a hydraulic generator to power only essential services - i.e. standby instruments and one radio.
The idea is to keep the aeroplane going while you try to restore power - by starting the APU for example. If you're out of fuel and the donkeys stop, the APU won't go either. It is possible to land the aircraft, as Air Canada already demonstrated with a 767, but its a heroic effort to make it work with limited flight controls and a high speed flapless landing. Still, they say any landing you can walk away from is a good one.