Hands down the Wicked Edge. Everything about it is easy and it makes everyone able to sharpen knives well. With time and practice, you can sharpen knives really well. The only thing not so easy about it is paying the price to buy one.
I use a very simple set of 10" medium grit ceramic rods for dull knives. Nothing beats a quality sharpening steel for quick and frequent touch-ups. End the day with a few passes on strop of your choice and you're gtg.
I do like a nice set of Japanese wet stones when I'm really working a knife, but they are a bit more effort to get out
Picked up a Work Sharp a couple weeks ago, and love it. Always struggled with free hand stone sharpening. The Work Sharp does a fantastic job with "tune-ups", but also great for re-profiling an edge. Also gives me the freedom to free-hand a bit.
And it works great on my axes, shovels, and hopefully lawn mower blades soon.
The most critical part about sharpening an edge is maintaining the correct or desired angle. Unless you have a lot of experience and that particular set of skills, free handing will lend itself to compromising the angle and producing uneven edges. For people without a lot of sharpening experience, I always recommend a sharpening system that allows you to set the correct angle and maintain that angle through out the sharpening process.
I personally don't sharpen my own blades. INGO member "7.62" does all of my sharpening. He uses a Wicked Edge system and his prices and turn around time are great.
Work sharp Ken Onion edition is on the list but for right now it's a Spyderco Sharpmaker. The Wicked Edge is great but damn it's pricey. I had one for a short time but couldn't justify the price so I sold it. It is one of the better sharpeners out there. Very fast.
It has served me well and adapts to a multitude of situations. The lansky is also built like a tank. I sharpen everything form kitchen knives to axes with it. Great for your bug out bag.
I've got a Ken onion and it is doing a great service for me, last weekend we butchered 7 hogs and the edge lasted through 5 hogs and I touched it up and finished the rest with the sharpest knife in the shop, (that's not much of a standard),
I did check one knife after pealing 4 hog heads it would still cut my arm hair.