Front door open of the HP ProLiant N36L
Looking at the innards of the Hewlett-Packard N36L once you open the door. HP gets a gold star for spartan yet fully-functional design.
Torx screws for disks are screwed into the door (along the bottom edge). The door also conveniently stores a Torx screwdriver, which is the only tool you'll need to work with this chassis.
If you're looking for more information, I've both a hardware review and software review of the N36L.