Last night I was lamenting the fact that I was going to the French Revolution without the TARDIS, and I realized that the imagination is just as good. Okay, for those of you who have no idea what I'm talking about, I stared Les Mis last night, and was sad that I was using my imagination to go to revolutionary France instead of the awesome, time-traveling, blue phone box from Doctor Who. You can learn more about the TARDIS here. WARNING: That page does include spoilers. The one that clicking on the words "Doctor Who" takes you to might also.
Anyway, whilst pondering my misfortune, I realized that the imagination is just as good as the TARDIS, if not as cool. Below is a list I created that compares the TARDIS and the imagination.
1. The imagination can take you to more places and to more times than the TARDIS can. But the TARDIS actually takes you there. You can feel, smell, hear, see and taste more when the TARDIS takes you somewhere. You're actually there. Whereas the imagination can't really take you anywhere. Generally. Only those with very vivid imaginations can actually go to imaginary places. (Yes, I'm one of them)
2. The rules for the imagination are...well, actually there really aren't any. Whereas if you travel by TARDIS you have to obey the rules of time travel and the Shadow Proclamation. Like no messing up the future or the past, there are fixed points in time that have to remain a certain way, blah blah blah. Nothing is certain or fixed in the imagination. You can change anything you want.
3. The TARDIS is bigger on the inside than the outside. In a way, the imagination is bigger since it can contain multiple universes.
4. The TARDIS is an awesome blue phone box with all sorts of buttons and pully things and telephones and zig-zag plotters and weird screens and universal translators and a swimming pool and a library (and sometimes a swimming pool in the library) and an engine that wheezes and whorps. Here's an example of the noises that the TARDIS makes. The imagination is a probably disgusting looking lump of brain tissue.
In conclusion, both the TARDIS and the imagination are very nice way to travel. If you want to go in style though, go with the TARDIS.