I think, based on how the different countries and authorities publish their stuff, you will have problems finding a valid source. The best and maybe most helpful way for sim flyers may be the free and payware on the flight planning software. They show the airways, high and low, and you can then click-generate some flight plan of your choice.

For lower airways, you can use the freeware Plan-G. I think older 1.x versions of FSBuild are freeware too. This would enable a rather powerful planning tool.

Charts for sim folks are sold by Navigraph. They should mainly differ in legal aspects, not so much on the actual data. I think they offer enroute ones too, at fairly reasonable prices. The products for the rw pilots are sometimes free, sometimes require a registration and sometimes are expensive.

for the USA and Alaska there is a free one

have a look at SkyVector
http://skyvector.com/

if you click on charts then Enroute High then you can select the parts of the usa you would like

Ive also found this site http://www.fltplan.com/ which covers USA and Canada, some stuff you have to register for and maybe pay but there is other stuff there that is free to use by the looks of it

You are right on EFB, it doesn't display the airways due to the way it was intended to be used. Not so much for the actual route planning, more for the route display. Sounds a bit clumsy first, but makes sense. The intersections are all present in the data though, you just don't see the lines as there is no real planning stage.

For paper charts, the Ebay tip is a good one. Same for the free opportunities on some countries, unfortunately not worldwide. For the rest, maybe search the old FSBuild releases, being freeware. I don't know if they support FSX though. Newer releases are payware and do support FSX of course.

For my airliner flying, I mostly import routes and then modify them in EFB. For the self planned ones, I still have good old Flight Sim Commander, but that's payware. It shows you the airways. I think Mark uses that one too. As said, for lower altitude flights, the freeware Plan-G lets you click-build plans, but that modern airliner stuff doesn't happen there.

What I've left out are those free and pay websites for the planning, not only route listings (which are mostly free). Those sites offer subscriptions of some kind and then allow to view actual charts or something. I haven't tried them, but just 'flew' over some of the advertisements. Maybe there's a trial period somewhere.
My memory is weak, I can't recall the name of some payware service I read about on some occasions.

Here's one I haven't tried. Just as an example. It's free I think. http://www.virtual-dispatch.net/?page_id=405
Mind the tips from the other folks since e.g. SkyVector allows at least for US planning, for free.

All ICAO countries (that is national states) produce their own airways charts relative to the country and airspace they manage. There is not to my knowledge a single world wide type chart but buried on the US FAA site is a link to some charts produced in large scale which effectively cover about half the globe, they are in PDF format and when you zoom them up they are fine for routes airports and navaids, they are of a size that was mean to go on a large overhead display or wall so they are very big.

Otherwise country by country, some publish airways charts that you can get for free others you have to pay for airways type charts. The suggestions abobe are all good ones. I find I do it country by country and where I have to pay to get a chart I see if I have a friend who has one or they have been posted at some of the various sim websites catering for virtual airlines as well.