I think we all came to an agreement with the follow the leader level as a least favorite as that was one you had to wait a bit for the lemmings to finish walking.
That doesn't come into consideration for me, as I grew up with the Mac version, which has fast-forward. Still, I feel "Follow the leader" is not an especially inspired level compared to others on the list; it's the same old "hold the crowd, leader does all the work, release" that you've had to do several times in a row at the start of Taxing. Making the holding pit with bombers is a slight difference but not enough of one.
Postcard From Lemmingland: 7
Tightrope City: 2
I Have A Cunning Plan: 3
Rainbow Island: 2 (-1)
Compression Method 1: 6
Tribute To M.C. Escher: 5 (-1)
Come On Over To My Place: 7 (+1)