For those not familiar with the show, "Doctor Who" is about the last of the Time Lords, a more or less immortal race of time-traveling beings (well, since he's the last of them, they're presumably not THAT immortal). Our hero, it should be noted, is not actually NAMED "Doctor Who"; he is simply "The Doctor"--his actual name is shrouded in mystery. He travels about in a TARDIS (Time and Relative Dimensions in Space) Machine, which is cleverly disguised as an old British Police Box (a phone booth). It's bigger on the inside, though--roughly the size of the bridge on the Enterprise, and that's just the part we can see. He travels the universe with a variety of human (and other) companions--most of whom are attractive young women. The women invariably develop debilitating crushes on the Doctor, but it's not clear that the relationships ever go beyond the chaste. But the relationships are not really the point: The show is a pure adventure, as the Doctor uses his galaxy-sized intelligence and a surfeit of technobabble to dispatch threats to life across the universe, always with a minimum of violence and bloodshed. The Doctor is about saving lives, not taking them.
As mentioned above, the show has been on the air in various forms for over forty years now. Time Lords, you see, can "regenerate," so when the actors and/or producers want to move on, they can easily be replaced simply by introducing a "new" Doctor. He's essentially the same character with the quirks and mannerisms of the new actor, fitted to the vision of the new producers. David Tennant (Dr. Ten) will soon be replaced by Matt Smith (Dr. Eleven). Perhaps of more disturbing significance, the executive producer, Russell T. Davies, will also be moving on. (Pay attention to the writing credits at the start of the episodes; the ones written by Davies are invariably the best.)
What makes the show special is that, for science-fiction, the production values are somewhat on the cheap side. To be sure, the recent episodes are technically far superior to those from the 60's and 70's. But the Daleks (the Time Lords' arch-enemies) still look like nothing so much as giant salt shakers with periscopes, and the extraplanetary sets look like, well, like sets. We're not talking "Battlestar Galactica," here.
But what the show lacks in technical dazzle, it more than makes up for in those less important areas like scripts and acting. The dialogue is often silly, but also quite funny. While the Doctor's enemies are often violent and inhuman--in every sense of the word--the writers are always aware that they are creating entertainment, and they do their best to incorporate clever banter and/or sight gags into every episode. The stories can be quite touching, too, without being overly saccharine. And when the script calls for technobabble--as any science fiction script eventually will--the actors are more than capable of pulling it off smoothly and convincingly.
The MOST impressive thing about "Doctor Who," though, is apparent when you compare it to other serial-type shows like "Lost" or "Heroes." Now, the Solipsist loves "Lost," but he's still not convinced that the writers know what they're doing or where the show is going. Every week, they throw in plot twists and wrinkles, which are certainly interesting, but sometimes incoherent. Each series of "Doctor Who," on the other hand (at least the recent ones), consists of a number of episodes, all of which are self-contained. Each episode, however, will introduce, however subtly and in passing, plot points that build up to a season finale. Only during the finale, though, do you realize that the whole season has been building up to this. So, for example, throughout the first series (starring Christopher Eccleston as The Doctor and Billie Piper as his companion, Rose), the characters encounter the phrase "Bad Wolf." It's nothing major or even particularly noticeable, until the end, at which point its significance becomes clear. (And then re-watching the episodes brings its own rewards, as you notice how the whole series was constructed.) In short, those Brit TV writers could teach their American counterparts a thing or two about plot development.
So, if you haven't already checked it out, start now. You can even watch the episodes instantly on Netflix. It's a pleasant way to pass an hour or two. You'll thank the Solipsist later.