I'm not really sure if it's what you are looking for but you could look at http://www.fallout3nexus.com/downloads/file.php?id=6395
or try out http://www.fallout3nexus.com/downloads/file.php?id=12300
The first link I have used, and it really does make it harder to find them. The second one I have not tried out.
I really like the randomized Bobblehead mod. It's so fun to stumble upon them when exploring.
You must have trees! Well, maybe not, maybe you don't feel the need. But if you do, I recommend this mod. http://www.fallout3nexus.com/downloads/file.php?id=2525 What I really like about it is that it adds some trees, and leaves quite a few of the old nasty ones so I'm not in a Disney movie. It still feels like the Wasteland to me, but I have some greenery. It's enough that I get quite lost in some places that I should know like the back of my hand (I played for a long, long time on the 360) and yet I can still see the big landmarks in the distance.