This list is constantly updated and has the most recent books I've read (listed on top of each category, both in English and Portuguese!). Please check back for new additions and feel free to leave any recommendations.
ECOLOGY
"Brazil and the Struggle for Rubber" - Warren Dean
"Voyage of the Turtle" - Carl Safina
"Watching Giants" - Elin Kelsey
"Cod - A Biography of the fish that changed the world" - Mark Kurlansky
"Sea Change - A message of the oceans" - Silvia Earle
"Wild Trees" - Richard Preston
HISTORY
"Guia Politicamente Incorreto da Historia do Brasil" - Leandro Narloch
"O misterio do samba" - Hermano Vianna
"Carlos Gracie - O criador de uma dinastia" - Reila Gracie
"The Accidental President of Brasil - A memoir" - Fernando Henrique Cardoso
"Africa - A Biography of the Continent" - John Reader
ARCHITECTURE
"Site Planning" - Kevin Lynch
"Plain Modern" - Malcom Quantrill
"Toward a New Regionalism" - David Miller
"Ten shades of green" - Peter Buchanan
SUSTAINABILITY
"Women in Green" - Kira Gould & Lance Holsey
"Break Through" - Ted Nordhaus & Michael Shellenberger
"Cradle to Cradle" - William McDonough & Michael Braungart
FICTION
"Cutting for Stone" - Abraham Verghese
"Olhai os Lirios do Campo" - Erico Verissimo
"O grande mentecapto" - Fernando Sabino
"One big damn puzzler" - John Harding
HISTORICAL FICTION
"Viva o Povo Brasileiro" - Joao Ubaldo Ribeiro