Pretty much what it says. I mostly use sharpening stones of different textures and haven't done much of it lately. I used to live near a knife store that did a better job than I could. $5-25 once a year wasn't a bad choice.

Now I want to get back into it. I wouldn't mind learning what the 'best' system is. Yes, I realize that's highly subjective. I'm trolling for opinions in this case.

RevDisk,

I am guessing you are going to sharpen pocket knives, fixed blades ( hunting/kitchen) and the like.

I have gone to diamond stones. My recommendations, and what I do use include:

DMT  : http://www.dmtsharp.com/

-Folding with coarse and fine. ( red and blue)
 http://www.dmtsharp.com/sharpeners/folding-models/double-sided-diafold/

-Credit Card : in all the grits.
http://www.dmtsharp.com/sharpeners/pocket-models/dia-sharp/

-Lansky pocket stone:
 http://lansky.com/index.php/products/diamond-pocket-stone/

-Eze-Lap Model H Diamond Sharpener This is the one I keep in my wallet.
http://eze-lap.com/hunting_fishing_outdoor_use/pocket-sharpeners/

That all shared, it is darn hard to beat a Norton 6" IB-6, fine/coarse grit stone. Great to get the old skill sets back, and great for sharpening. NOTE: I do NOT use oil on these or Arkansas stones.

I'd snag a stone, some carbon steel knife, and work on the basics. One tip, is to use a sharpie marker run along the edge. This allows one to see if they are keeping a consistent edge.

alone

Of what I own, these are my preferences in the order I prefer them.

1. Work Sharp Knife and Tool Sharpener--My hands-down favorite. It has a learning curve to it. Start with cheap dollar knives before working on your expensive stuff. Sharpen any size blade, from the smallest Old Timer blade to a sword with no problem. Puts a convex edge on the blade. Once you get good at angles, you can throw the guides away. I don't have the new Ken Onion Model yet, but I hear really good things.

2. Lansky System--Easy to use, does the job great. Needs a little tape on the jaws to protect the blade's finish. Good for medium knives, 3-6" long, and they need to be fairly wide. Perfect for maintaining a v-ground edge.

3. KME knife Sharpener w/ diamond stones--Expensive, but worth it. Very adjustable and easy to work with. The diamond stones are the way to go with this system. The ceramic stones, which are cheaper, are not great and wear out easy. Good for 3-8" blades, and they need to be fairly wide. Perfect for maintaining a v-ground edge.

4. 1x30 belt sander--Great for major reprofiling jobs. Watch out for overheating. Dip the knife after every few passes, and do not press too hard or you'll scorch the steel.

5. Spyderco Sharpmaker--Decent sharpener. Some guys can get their blades really sharp with this thing, but it's never worked great for me.

6. sandpaper and a mousepad--One of the easiest way to sharpen a convex edge. A light, light touch is needed. Let the sandpaper do all the work. You can get some scary edges after you practice a while.

7. Japanese waterstones--They do the job pretty well, but are really expensive, especially the good ones. Great for scandi edges.

8. Norton India stone--Cheap, and they work great once you get the basics of sharpening down.

Every one of my knives gets stropped at the end of the sharpening regimen with a DLT block strop that's loaded with black, green, and white buffing compound. For my toothy edges, I only strop with black compound. For my polished edges, I strop on all three.

A length of cheap leather belt with buffing compound on it works great as a field hone. Add to that a few pieces of sandpaper, using the belt as a backing and laid on a flat rock, gives you a dandy field sharpening kit.

Another decent improvised method is paint sticks with sandpaper glued to them. I use 3m spray adhesive to glue it together. Works surprisingly well for v-ground and scandi edges, but will convex those edges over time.

A more commercial option for a field kit is the Work Sharp Field Sharpener. Two diamond hones with guides, two ceramic rod options, and a strop all in one unit. It works great, and is easy to pack around. I'd still add the piece of leather belt for stropping, though, since the strop on the FS is a little shorter than I'd like. 

Hard to beat the combination of a stone and strop but it can take some time time.  In a pinch one of these works really well to hone the edge.

http://fetznerspeedysharp.net

louie the lumberjack

I use the old tried and true "whet stones."  No that's not a typo.  I have several, from coarse, through varying grades of medium, to fine.  Included are two blocks of wood wrapped in leather, the back of a note pad, and a can of kitchen approved honing oil.  I manage to put a mirror polish, and a razor sharp edge on a knife with these primitive tools, my two hands, and my tri-focaled eyes.

The key, no matter what "system" you use, is practice.  I've picked up an already razor sharp knife, just to see if I can make it even sharper.  I have several "practice" knives, which I'll purposely dull, and re-hone. Or I used to.  Nowadays, I get plenty of practice with customer's knives.

I started making knives when I was a teenager, and there are still more sharpening devices out there than I have ever used.  As with anything, skill counts for more than what you use.

If I had to have only one tool for sharpening knives though, I would take the course DMT folder alone mentioned above.

At home I like the Spyderco Tri-Angle Sharpmaker.  For a quick touch up in the field I found the Hunter Honer to strike the right bakance between effective and portable.

Of course a good set of whet stones works too.

They're only really good for a convex edge.  I haven't been able to get a flat grind with one to save my a**.