Heres two sets:
You said you wanted some overgrown jungle/sci-fi stuff, which is entirely what Crysis 3 is so heres the concept art for that game.
http://www.neoseeker.com/crysis-3/concept_art/
Also Star Wars The Old Republic has some nice art used in a lot of the loading screens.
http://www.swtor.com/info/media/concepts
Enjoy the art and happy birthday!