Sharpeners largely depend on the blade shape and edge type.
This is field work sharpening.
For "easy " shapes like a standard clip point, drop point, spear point or pukko, without serrations I tend to use the DMT DIAFOLD (2 sided diamond stone linked to by others), a Spyderco Double stuff pocket stone (the 2 grades of ceramic used in their Triangle sharpener, but flat simmilar to a 3/4"x4" stone).

This is done more at home. (one of the above stones is there to fix nicks and gouges in the edge while out in the field).
Some of my blades and all my axes/hawks have a convex edge so I use a piece of wet-dry sandpaper in varying grits on a strop board (wood bord with leather pad, mine has polishing compound addded to the leather)Or you can do the sandpaper over a mouse pad.

This is both Field and home techniques.
Then you get into inward curving or undulating cutting edges (kukri, karambit, etc) these tend to take a round (diamond rod, round or 1/2 round file, or round ceramic rod), triangular (various ceramic sticks) or convexed (the top of some old sanding blocks) sharpening surface.

The pull through style sharpeners are ok for basic edge shaping in my experience, unfortunately with some knives they tend to leave a bur on the edge and require a light touch on one of the above mentioned devices to finish the job. Case in point I sharpend a friend work knife yesterday that she has used a accusharp on for about 2 years, 5 minutes touching up the bur and getting it shaving sharp.

Other things play into what a specific blade needs to be sharpened. Harder steels seem to work with pull trough sharpeners better, softer steels seem more inclined to like being caressed with files, ceramic or natural stones, while the in between hardnesses like most of everything with an occasional touch up on one of the first three methods.

There are also various angle guide tools to maintain the sharpening angle. I have used a few, they help when learning to sharpen by hand for some people.

Over all, it seems to be a trade off of space and weight for the method(s) you choose to sharpen with. Axes and machetes can both be repaired with a file in the field but, is the extra weight of the file or files necessary? Are any of your other blades soft enough to not force the file to slip off it whitout removing metal?

I have carried the Spyderco double stuff stone for nearly 10 years and the DMT diafold fo almost 8. They work for me for my EDC blades. I have pull trough sharpeners or back up diamond rods in most of my bags or packs I use.

Just throwing some of my seldom useful information out there.