Some of the modern ones (notebook out Hodgie) really vary. Favourites include Roary the Racing Car, Pingu, Mio Mao, Timmy Time and Space Pirates are excellent.
However some are hilariously awful. The king for me is Garth & Bev. The only way to have come up with this concept was to take a serious amount of Class A drugs. Here's a brief synopsis:
Garth and Bev are basically a couple of Irish gypsy children living in the Bronze Age. Their mentor is the twin brother of Getafix from Asterix who basically leads the kids along until he basically tells them the answer. In every episode a story evolves where some problem occurs and a solution needs to be found. In one episode they carry pots for the local potter and they keep hitting each other and breaking. After much prompting from the bearded druid they work out shoving frogs with fat air-filled cheeks between stops the pots from breaking. Queue beardy who rewards them by sending through the 'time spiral' to land in Mr Dunlop's room whose just invented the pneumatic tyre. Tyres / frogs cheeks, geddit? Dunlop looks shocked and surprised at the appearance of two feral sprogs magically appearing in his lounge who proceed to tell them they invented what he's just done with frogs faces, only to say 'well we'll be off now, top a da morning' and back through a time vortex.
I'm not making this up!
http://www.youtube.com/watch?v=403Kt3Pw ... ata_player