New Zealand Government has set up an official website targeting Singaporeans to migrate to New Zealand. Check out the website here.
Natural environment wise, New Zealand is fantastic, with great landscapes and low population density. Due to its faraway proximity and buffer in the form of Australia, it is the least likely country to be affected in World Wars.
Only potential downsides are natural disasters (earthquakes), and possible employment difficulties. I have heard anecdotal stories about people migrating to Canada (another low population density country) and then having a hard time finding jobs.