For good bandwidth testing, try here:
http://jlab4.jlab.org:7123/
I used to use speakeasy or speedtest, however I have noticed they can't test fast enough, became to popular, and got bogged down.
Connected to: jlab4.jlab.org -- Using IPv4 address
Checking for Middleboxes . . . . . . . . . . . . . . . . . . Done
checking for firewalls . . . . . . . . . . . . . . . . . . . Done
running 10s outbound test (client-to-server [C2S]) . . . . . 22.23Mb/s
running 10s inbound test (server-to-client [S2C]) . . . . . . 20.70Mb/s
The slowest link in the end-to-end path is a 45 Mbps T3/DS3 subnet