Map designs are difficult to come up with I agree, and everyone has different ideas of what makes a decent map.
As we all know, the main thing that limits us is Far Cry 2 itself, both in resources and the items available.
Often a bit of time off can work wonders, if I run out of ideas, a couple of days off usually jarrs something loose lol and I'm back to mapping again.

I'll throw a few of my ideas around - hopefully they might give you some ideas
I personally like architectural maps, with lots of custom structures, or just one big one. I also like to recreate scenes from my favorite movies too.
Occasionally I attempt both - an architectural map based on a movie.
I also like to recreate famous landmarks too, as accurately as the game allows, although my landmark maps don't play that well, I just like making them to look pretty

(although that's a matter of opinion lol)
I've seen many maps that recreate levels from other games, while some of these are very good, I find that unless the look of the game matches the brushes in Far Cry 2, then it tends not to look that great.
I've been playing a bit of Red Dead Redemption, and some of those areas would match ok, but it's mostly rocky deserts and cliffs etc. The buildings are quite interesting though. It might be worth a try to make a map based on one of the forts, or maybe one of the small towns.
An idea I've just had - what about a map contained inside a giant PC. All the internals would be there eg. Hard Drive, Motherboard, RAM strips, CPU cooler, Power Supply etc. It would be like an urban style, close quarter map.
Oversized maps have been created before, but I'm not sure if a giant PC has been done, maybe it has, but it still sounds pretty interesting

I have a map that has been sitting there for a while, waiting for some inspiration, it is a giant, vertical spiral, with a globe at the top and bottom.
I have called it 'Uzumaki' (Spirals) after a Japanese film of the same name. It doesn't have anything to do with the film, except the name.
I don't really know where I'm going with it, but if you want we could complete it as a co-op project, maybe you can come up with something - I would really like to get it finished, it's quite unusual.
I designed the spiral as part of an experiment into designing odd and unusual shapes - I've got a giant apple map and a huge vase map too lol, they are all sitting there waiting for ideas, not sure if they'll get any though

I'm sure none of these ideas are original, but it's all about the details - that's what makes a normal map great in my opinion.
Good luck, I hope you get some inspiration soon, I'm sure you will
