Here you go, the greatest 6 compound movements of all time (in no particular order):
Barbell Curls
Dumbbell Curls
Cable Curls
Dumbbell Concentration Curls
EZ-Bar Preacher Curls
Cable Supine Curls
I'd have to say that wrist curls come in a very close 7th.
JOKING!!!
Here are the 6 exercises I'm currently doing for my 5x5 routine:
Squat
Deadlift
Bench Press
Military Press
Rows
Chin-Ups
Those 6 are great, and they cover pretty much your entire body. You could add in something specifically for abs if you want. You could also substitute in dips, incline bench press, front squats, any deadlift variation, and [others].
Alternatively, you could use the Olympic lifts and maybe one or two other movements.