A really good lyricist with good flow and breath control. Set the bar for a good LP when he dropped Illmatic, probably the best rap CD of all time. Fell back slightly when he dropped It Was Written in '96, but it still had some good songs. Nastradamus kinda sucked too, but Nasty Nas made a comeback with Stillmatic and God's Son. Then he went on 2004 to drop Street's Disciple, his first double disc CD. Yeah, and he shut Jay-Z down too.
Some good Nas songs are:
'N.Y. State of Mind', 'I Gave You Power', 'Memory Lane', etc.