[Rainbow Six]

I'm inclined to suggest a Survivor's Guide to the USA. I presume it's an area that would be of interest to many consumers, so could be expected to be financially successful for the company and gamers would - hopefully - get use of out of it.

Now, creating a Survivor's Guide to the entire USA is likely to be something of a gargantuan task, which, if not done well, could result in something of a backlash. That being the case, perhaps FL could split the US into regions, north east, south east, west coast, etc, etc. They could then release regional sourcebooks over a period of time, maybe once every three to four months, thus alleviating the time pressure to churn out a tome on the entire US in one go.

That would probably take at least eighteen months - two years to complete (I'm guessing you'd probably want to split the US into what, six or so regions?), and would represent a continuous stream of fresh material coming out of the pipeline on a regular basis.

As an aside to that, perhaps they could release adventure modules to use with the sourcebooks on a possibly less ambitious scale, i.e. one module for every two sourcebooks. And mix it up a bit. Release two US Sourcebooks then release a Middle East Sourcebook, then another US then one based on a part of Europe.

While it's not my particular thing, 'gun guides' (for a lack of a better term) have featured in every version including 2013 so presumably there's a demand there and could probably be produced relatively quickly.