The last Lenovo/IBM laptop with a good screen was the T60p. I believe they actually used IPS panels for that LCD screen.
The only good screens on Lenovo laptops these days are in the tablets. I know for a fact that the X200 tablet uses a good panel with decent colors and viewing angles, although it is hampered somewhat by the digitizer. It is possible to replace the LCD panel in some Lenovo models with other panels of higher quality. Here is an example of one such modification: http://forum.notebookreview.com/showthread.php?t=366472