no
As of the 2008 Games in Beijing, no athlete from Madagascar has ever won an Olympic medal.
No.
Yes
No South American country has ever won a winter Olympic medal.
Marcos Baghdatis had no Olympic medals.
No. As of the 2008 Games, no athlete from Malta has ever won an Olympic medal.
No athlete from the country of Samoa has won an Olympic medal. Samoa first participated in the 1984 Los Angeles Summer Olympic Games.
No, but they will win either Gold or Silver this year (2012). They lost in Mexico City (1968) against Japan for a bronze 2-0.
Nadia Comaneci
Brazil
No. Brazil has been represented at the Winter Olympics since 1992 by athletes participating in alpine skiing, bobsleigh, cross country skiing, luge, and snowboarding without winning any medals.
Yes. As of 2010 Alexandre Bilodeau won the first ever Olympic gold medal for Canada on home soil. He competed in the Men's Moguls.