What adapter do I need for my TV, Display or Projector?
Apple's article http://support.apple.com/kb/HT3235 covers most of the cables needed, except for some Thunderbolt Macs.
If you have a Thunderbolt Mac, one of the Thunderbolt to HDMI Adapters might be needed for HDMI, one of the Thunderbolt to Dual-Link DVI for Dual-Link DVI (for devices such as Apple's Cinema 30-inch HD Flat Panel Display M9179LL/A), one of the Thunderbolt DVI adapters for regular DVI, and one of the Thunderbolt to VGA adapters needed for VGA.
With pre-2006 Macs, the iBook article from Apple covers iBook adapters.
The 12" Powerbook article covers those Powerbooks.
For those wishing to connect their AppleTV as a display, this user tip explains what an AppleTV can do, and can't do, and what alternatives exist.
I have no affiliation with Amazon or the distributers selling those adapters, or knowledge if the links from Amazon are working adapters for your configuration.