Here are the recommended connection speeds for many popular broadband activities. If you are doing multiple things at once online or sharing a connection with multiple computers, then these recommended speeds may not be enough.. All speeds are provided in the Speedtest.net default of mbps (megabits per second).
Skype (source: Skype Support)
Important note: these connection speed requirements include downloading and uploading at the same time. Since Speedtest.net tests download and upload separately for accuracy, your results will need to be higher than the the numbers provided above. For example, your upload speed may be 2 mbps in the Speedtest.net result, but may go down to 1 mbps while your connection is downloading something.
Netflix (source: Netflix Help)
YouTube (source: YouTube Help)
YouTube offers several quality levels for videos that you can use. The lower-numbers (360p) indicate that the video is smaller and uses less bandwidth, but also has less detailed. The more detailed the video (480p, 720p), the more bandwidth it takes to stream. Choose the highest video quality that allows you to stream without repeated stops and starts.
Hulu (source: Hulu Help)
Hulu also offers several different quality levels for different connection speeds. Using the gear icon under videos, you can tell Hulu to "Auto-select the best quality for my bandwidth (recommended)".
Online Video Games
For playing video games online, download and upload don't matter as much as ping, which measures how responsive your connection is. The lower ping to servers and other players, the lower the "lag" will be in your game. To lower ping, you can take steps like connecting your computer to the router using ethernet instead of Wi-Fi, and not downloading/uploading files while playing games.
Spotify (source: Spotify FAQ)
The bandwidth requirements for Rdio are similar, though both services offer a low-quality option for slower mobile connections.