Recommended Sandbox Maps?

I think this is the most appropriate place to post this.

Anyway, I am looking for some maps for a Sandbox server.
They don’t necessarily have to built strictly for a sandbox, but more to follow some of these…
*Not an eyesore.
*Have at least some large areas for building.
*Be fairly interesting and unique.

Only 100% confirmed map we have is Huge Flat Construct, all suggestions are very welcome.
Thanks.

gm_construct_flatgrass_v5
gm_botmap_v3

Freespace06_v2-1 Freespace03 Freespace06_v1

gm_mobenix,gm_ps_hugeflatconstruct_svn

gm_wireconstruct_rc
Has a large flat-grass like area on top then a bunch of stuff underground

gm_flatgrass_revolution, gm_flatgrass_construct_v5

gm_flatgrass2008

http://s3.garrysmod.org/img/dl/47709_2.jpg

Thanks for the recommendations guys! I was looking for flatgrass2008, simply didn’t remember the name!