My Opinion...
Top 5
PowerMac 9600 - A Monster of a Machine that wasn't replaced till the G5 tower
Pismo - Many expandable lessons here for apple to follow for their current laptops!
PowerMac G5 - the first Mac that was actually fast enough - I expanded mine with raid and video cards
Quadra 840 AV - The og monster box, I did things on this box that converted every PC user that saw me working on it
7300 - an iron work horse that I found in almost every Mac based office, it worked worked worked
Bottom 5
6400/6500 - The worst machines to upgrade - ever, I can still point out the scars
Performa **0 - Apple should apologize for all the performa triple digit machines
Quadra 605 - I don't know what the engineer was smoking
LC 575/580 - These machine were so slow that no one wanted to use them- no fpu
og iMac - I don't know why anyone liked these bulky, slow and non-upgradable machines (I want to like the screen- shut up and get to work!)