Two blades are a must - it's surprising how many times a smaller blade is useful (eg. prying the back off something with a very narrow gap).
The screwdrivers are my most commonly used/useful tools in everyday life - tighten a hinge or a handle, stuff like that.
Most of the others are occasionally useful - I've used the awl for emergency repairs on tent stitching - but the above are the ones I'd rate the most.