Try running a speedtest to see which gives you the best.

AMS1: http://speedtest-ams1.digitalocean.com/
AMS2: http://speedtest-ams2.digitalocean.com/
NY1: http://speedtest-ny1.digitalocean.com/
NY2: http://speedtest-nyc2.digitalocean.com/
SFO1: http://speedtest-sfo1.digitalocean.com/
SGP1: http://speedtest-sgp1.digitalocean.com/

You can also ping the hostnames to measure the latency.

Hi JT,

Thanks for the fast reply!
Problem is I'm not from Brazil but am building a website for Brazilian audience.
What else could I do to find out which region is the closest?

Thanks,
Michael

The closest location would be New York. Next up would be either San Fransisco or Amsterdam, depending on where the user(s) are in Brazil. Though the difference is likely negligible in that case.

Hi Bryan! Thank you very much.

Ping times from Sao Paulo:

AMS1: Average = 228ms
AMS2: Average = 244ms
NY1: Average = 156ms
NY2: Average = 162ms
SFO1: Average = 229ms
SGP1: Average = 415ms

Brgds Patrick