The biggest and the latest amongst these is Bagger 293 (aka Tenova TAKRAF SRs 8000 and formerly known as RB 293). It holds the records for the largest terrestrial vehicle in the Guinness Book of Records.
Built in 1995, it has a gigantic length of 240 metres, height of 96 metres and weighs 13,000 tonnes. The size of its impeller is 21.6 metres - almost reaching an eight story building. Compared to it the length of famous NASA crawler, which transports space shuttles to the launch pad, is mere 40 metres.
Few pictures of other models are shown below;
Image from Flickr is by mush2274
Image from Flickr is by [ henning ]
Badger 288 while crossing a highway;
Image from Flickr is by metaphorge
As per Wikipedia;
Image from Flickr is johanwieland