Hi, well, this is definitely going to be a very useful thread, I hope...
I´ll start with the good, old Commodore 64:
Tape: load (Return)
Disk: load"*",8,1 (Return)
load"$",8 (Return) (to load the program list)
Of course, most emulators have an autostart feature... but you may do it the old-fashioned way...