BB Max: A good basic Broadband tester for Download/Upload speeds.
Subscribe free to login and store your results over time
BBC iPlayer Streaming Speeds for iPlayer services
BroadBand Speed Checker: See also the results from your neighbours
on a map
(if they have supplied test information)
BT Tester: The "Official" BB Speedtester used by BT and ISPs.
This is the BT standard tester used by engineers. Select your connection - and do not reuse too frequently