DisplayMate has perform extensive testing of LCD, IPS-LCD in Apple's iPhone 4, AMOLED (in Google's Nexus-One phone) and the Super-AMOLED as used in Samsung's Galaxy S phones. The bottom line is that the Super-AMOLED and IPS-LCD are both great displays, but they say that the iPhone's display is the ultimate winner.
The IPS-LCD is brighter, has higher pixel density and consumes less power. The Super-AMOLED is better in sunlight (less glare) and has much better contrast ratio - blacks are really blacks. The colors on the Super-AMOLED are oversaturated, while the colors on the IPS-LCD are undersaturated. Interestingly, a 'plain' LCD as used by the Motorola Droid has the best picture quality and accuracy.
When Engadget did their own testing of the two display technologies (Super-AMOLED vs IPS-LCD), they came pretty much to the same conclusions. Now we have numbers backing those tests...
