5) The Death Merchant
Of all the craziness our time travelers witnessed, the strangest thing has to be the sight of Niccolo Machiavelli walking his dalmatian through a Civil War-era battlefield in full daylight. Yes, you read right: in what is sure evidence the writers were just picking historical ideas at random at this point, everyone's favorite Italian strategist/philosopher/asshole tries to manipulate the outcome of the War Between the States just cuz, a situation that's complicated when Tony loses his memory. But the oddest thing about this is the show's nonsensical concept that because he already died in history, Machiavelli literally cannot be killed in the nineteenth century. Bullets get fired into him and he just laughs (that and his absurd wardrobe make him seem more than a little Dracula-like). Even for this series, time travel granting you immortality is a bit hard to swallow, and it's weirdly one of the few bits of continuity the show has, as an earlier episode floats the same idea. If so, how come Tony and Doug are at risk when they travel to the future? Huh? Or anywhere, for that matter?
Head-spinning pseudoscience aside, this is still a (relatively) great episode because it has a few more turns than usual, and the chocolate-and-anchovies approach to combining historical periods suggests yet another road the show could have taken, had it lived longer. If nothing else, we get some more immortal dialogue: "We're not going to kill you, Machiavelli! No: we're going to tie you up and put you in that cave!"
4) Rendezvous With Yesterday
If you only watch one episode of Time Tunnel, and there's no real reason why you should watch any more than that, you can't go wrong with the show's premiere. It's got everything: the mysterious opening with the car disappearing under the desert, the shots of the interior of the complex, and the classic dilemma of trying to fix an unalterable point in the past (which might have been more surprising had it not been given away by a big fat establishing shot before Tony landed).
Also, because it has to establish the premise that will carry the show, there's a lot more happening plotwise here than in most of the other standard capture/escape/fight/leave episodes. The most interesting origin story given here by far, however, is the explanation for why Doug wears that gross suit and tie all the time: it was a disguise to blend seamlessly into 1912, you see, and he's been wearing it ever since, except for when he doesn't and then suddenly he's wearing it again next episode and I'm already losing interest halfway through this sentence. Your guess is as good as mine when it comes to Tony's turtleneck. I suppose that leaves room for a prequel...
3) Secret Weapon
Landing in Soviet Russia in the 1950's, Doug and Tony are given a new mission from the future in a weird melting rectangle to infiltrate a secret government project. They do, and surprise: the Russians are building their own time tunnel and want to use these American chumps as guinea pigs!
The Cold War metaphor may be layered on a little too thick, but it's refreshing to see the main characters actually involved in a real time travel story, rather than just being fish out of water: we also get a little more background about the project, for what it's worth. With a little more effort, the scientist Doctor Biracki could have evolved into a tragic figure, or perhaps a recurring villain. Then again, with a little more effort I probably wouldn't have needed to write a "Least Terrible" list at all.
2) Kill Two By Two
Pretty much every Time Tunnel episode had at least one villain, but not all of them were memorable and some were pretty damn boring. Out of the whole show, the Japanese-American actor Mako hands down played the best one, a downed WWII fighter pilot named Lieutenant Nakamura who decides to pull a Most Dangerous Game when he discovers Tony and Doug on his island.
Although the story does play on the stereotype of Japanese people as being overly committed to honor and duty, it also gives us by far the closest thing the show ever got to a morally complex antagonist, someone with tragic and understandable motives that made them a lot more interesting to watch than a guy with goofy green makeup on. It's hard to think that just 13 episodes later, we'd go from this to aliens that look like sparkly purple versions of Wilford Brimley, but so it goes.
1) The Day the Sky Fell In
Ok, once again we have to make a major caveat for this episode: yes, it's set during the bombing of Pearl Harbor, and nearly all of the Japanese characters are scheming bad guys, thugs and/or servants. So why give this the time of day? Because it's the only episode the show produced that even tried to wring pathos out of its heroes' backstories. See, here (and only here) we learn that Tony used to live in Hawaii with his family as a boy, and that his military father disappeared during the raid. This sets up the predictable but satisfyingly tragic arc where Tony struggles to change history by warning his Dad about the surprise attack: needless to say, it doesn't go according to plan, but there's a genuinely crushing scene toward the end where we actually sort of feel for our turtleneck-wearing time traveler.
Of course, next week it would be back to fights, escapes and FANTASTIC ADVENTURE! But at least we have this one demonstration that the show did have some depths, however seldom it plunged into them.