Have your alternator checked for shorts!
It sounds to me like you have a fairly low resistance path to ground from the positive terminal of the battery. Since you have eliminated the battery and starter, the next most likely item is the alternator. The alternator has isolation diodes in it, and if one or more shorts, it will cause your battery to drain in no time at all. There is no fuse between the alternator and battery, so disconnect the alternator to remove it from the circuit and see if the battery will hold a charge with the alternator out of the system. A previous reply told you to check the fuses, also a good step. HINT: If the alternator is the culprit, you should be able to feel that it is very hot about an hour after shutting the engine down. This is due to current flow through the shorted diodes into the windings of the alternator. There aren't really very many things that could cause your battery to discharge as quickly as you say except the alternator. Another possibility, but quite unlikely is a defective glow relay box. It is mounted quite near the windshield washer reservoir on the driver's side inner fender.