TARDIS (Time and Relative Dimension in Space)
The Doctor's TARDIS, a product of his home planet of Gallifrey, enables his ability to travel through time and space. The Time Lord technology is superior to ours in so many different ways; most importantly, it's bigger on the inside (see bottom left picture); there are also rooms branching off of the console room, such as a library, a wardrobe, and a pool. It may appear to be made of wood externally, but it is nearly impossible to breach from outside- even by Weeping Angels. Even though it may seem odd to have a phone box from the 1950's popping up around the galaxy at various points in time, the TARDIS has a shielding device that causes any passerby to not notice it or think it strange. The door locks and has a key; more keys can be made from the walls. However, despite its seemingly extraordinary design, it has only one door, so exiting is limited. The console is also large and difficult to operate on one's own (especially if said person didn't pass his driving test). If one is traveling in company, however, operation is easy and fun (see bottom right picture). The TARDIS does not come with a fire extinguishing program inside, so fires (as shown in the center picture below) are very dangerous and require extensive repairs to the control room. There are also updated models and versions, but the other TARDISes were destroyed with Gallifrey and the Time Lords. Due to these drawbacks (despite the otherwise impressive technology), the TARDIS earns a respectable 2nd place ranking.