Arsenal of Democracy

Arsenal of Democracy is a computer game that is a spin-off of the Hearts of Iron series. It is an strategic level simulation of the period surrounding (and including) WWII.

It has a number of interesting features, several excellent ones, very few bad ones, and is a quite absorbing game to play.

Some real pros for me:
You can start as early as 1936, or well into the war. There are even several post-WWII scenarios running into the 1960's.
You can play as any nation. Yes, you can play as El Salvador or Yugoslavia if you want (there are AARs on the game's forum where people have done both), though don't expect to get far. :-)
They'd tried very hard, and IMO succeeded, in striking the proper balance between playability and realism on the economic & industrial front. A few examples: production needs a number of things, including resources (Energy, Metal, and Rare Materials), factories, and infrastructure (which acts as a multiplier for the factories - with no infrastructure a factory doesn't produce anything). You don't just order units at will - setting up a production line requires 'retooling' time (several months) during which no progress is made. Further, each serial build on a production line is a little faster (up to a point, of course). It is thus MUCH more efficient to build ten units in series than it is in parallel, though of course parallel builds are worth the trade off sometimes.
Logistics are extensive and vital, but still simple enough (and can be automated) to be used. Units require various amounts of 'supplies' and oil, and use more when in combat. You really need good supply lines to win, and they are vulnerable to attack.
The gameplay is smooth, and very addictive. Just one more week... wait, new tech, gotta retool my production... stand down the air attacks so they can upgrade... maybe I'll just keep playing 'till they're done...
The game is easy to mod. Very easy. If you can edit a text file, literally, you can mod this game. This solves the biggest problem with the game IMO...
Con:
They nerfed the USA. OK, a lot of WWII games do that. If you don't the end result is more or less a foregone conclusion. To their credit they nerfed it a lot less than some (I'm looking at YOU, Strategic Command: European Theater), and thanks to the high modability you can un-nerf the US.
My second-biggest complaint: you get messages telling you how various historical turning points turned out (annexations, treaties, incidents, etc.) which is good, but there seems to be no way in-game to figure out what the situation was! OK, everyone playing this type of game is going to know what "Germany claims Sudetenland" means, but I had to look up "The 2-26 Incident" (attempted coup in Japan, which may or may not succeed in game) and I'm something of a WWII buff! Events which you actually decide on or happen primarily to your country get explanatory text, but the notification you get when they happen to someone else seems to have no way to access that text. :-(

A single unit is a ground division, capital ship or group of lighter ships, or a wing of aircraft. The map is region-based, not hex-based (a minor con). I spend quite a lot of my time on the production screen watching my builds and managing my economy, rather less on actual combat ops. Units also need leaders (historical generals and admirals) who have varying skills and special abilities. Research teams have both skills and specialties: Boeing will research an airplane tech a lot faster than the New York Naval Yard, but the NYNY is much better at ship tech. You are actually much better off assigning a low-skill team that closely matches the tech to research it than a high-skill team that doesn't. Tech teams and your political leaders, who also have various abilities, come and go over time; quite appropriate, since a full game lasts 28 years!

All in all a great game, especially for only $20.