Both my children adore Tractor Tom, and the youngest (2.5) cries if we try to put anything else on! The storytelling is very, very good, and the characters all bounce off each other brilliantly. Especially in Season 2, where the machines are given voices.
There are no "bad guys", no good vs evil, just simple, clever, funny tales of the everyday muddles people (or in this case, Tractors) get into, and how friends are there to help each other out.
It's a REAL shame the series was cut after 2 seasons of 26 espisodes, but what we're left with are timeless modern classics which children of all ages will love.