Nunu vs Lee sin

Nunu is the least favorite jungler for me to see on the enemy team. He will walk in, smite consume, then blood boil and run out.

Nunu is suited to objective control and being a Frontline tank and his late game is very strong IF you can full channel that ulti. Lee Sin is better at invading the jungle with the intent to duel/kill the enemy jungler rather than straight counter jungling. Lee excels at early ganks because of his mobility, soft cc, and high damage pre-6. Late game Lee is rather disappointing unless you have greatly snowballed and are building full damage, otherwise his only uses are "the insec" and dragon/baron steals.

Counter jungling.. well nunu is good at the "get in get out" lee sin is more of the "go in kill sm1 get out" pick your poison ^^