Well a pull through sharpener, though I don't recommend them. Takes off two much metal, questionable edge.
Then a motorized knife sharpener, but word of mouth says only the most expensive are worth anything. Not sure how they handle EDC knives.
Worksharps are fast, as are belt sanders. But they work too well and if you don't know what you are doing, you may take off two much metal.
Stick set ups like Spyderco Sharpmaker are easy to set up. Not great for setting a new bevel, no flexibility in choosing angles, and it is questionable what angle you really have them set to
Complex jigs like Edge Pro and Wicked Edge are precise, but eat up space, are expensive before you upgrade the stones, and take time to set up.
Freehand is quick and easy with the right stones, if you know what you are doing. Very subject to human error and it takes time to learn to hold an angle throughout the process. OTOH you have the largest selection of abrasives/stones, fast and portable set ups, and have the least limitations on blade geometry.
All in all, probably the Sharpmaker or its like.