14 Reasons Why We Love The Deadly Assassin
All hail!

Best. Opening. Scene. Ever.
What?! It's the Doctor! Firing a gun! At the President! (Apparently) Actually, he's not. But after an opening like this, even the four-minute warning, or Valerie Leon stripping down to her beaver on ITV wouldn't have been enough to tear us away.
The Time Lord Costumes

Costumes and headgear so blisteringly iconic that even the Russell-era show, with all its queasiness of anything too embarrassingly Classic, thought they were good enough to keep on. Their designer, James Acheson, we remind you here, is now a three-time Oscar winner, though did he mention Doctor Who in any acceptance speech? Did he fuck.

Conspiracy Chic
It's the nearest Doctor Who's ever come to the labyrinthine playfulness of Homeland or The Parallax View. What are the chances the creators of 24 were watching The Deadly Assassin when they dreamed up their show? (None at all, probably)
The Secondary Console Room

Pity they never nailed the look of the TARDIS's alternate console room. Its Gallifrey by way of the Garrick Club stylings might have survived beyond season 14, had Barry Newbury built some movement into the design. Still, it's a handsome piece of set, despite the whiff of High Tory decor.

No Companion!
Even the 2009 specials failed to find the balls to make the Doctor totally assistantless. Moffat said recently that the programme's central character is always the companion. The Deadly Assassin proves that, when done right, we don't always need a human to sugar the pill of the Doctor's full-on alienness.
The Colour Green

Try thinking of the story as any other colour. It's green!
It Pissed Off The DWAS

"As a Doctor Who story, The Deadly Assassin is just not worth considering," moaned Jan Vincent-Rudzki in the pages of TARDIS, his bottom lip no doubt sticking out. "I've spoken to many people, and they all said how this story shattered their illusions of the Time Lords and lowered them to ordinary people." Thirty years on, JVR was still huffing about the humanising of the Time Lords on the DVD release documentary, and probably still thinking The Hand of Fear was better.
The Master's Eyeballs

The whole costume is a masterwork in gruesome design, but the signature splash of genius is in the eyeballs. Check out The Keeper of Traken, which re-used the Assassin costume, but chickened out of the eyeballs, to see how integral they are to that Master's visual power.

It Pissed Off Mary Whitehouse
Anything that managed to get bothersome cultural arsonist, Mary Whitehouse, and her brigade of undersexed curtain-twitchers in a lather of puritanical outrage, is always a good thing. Except here, where the downside was that the BBC caved, snipped down the offending cliffhanger and sent Philip Hinchcliffe packing off to Target.
Pea-Ow!

That Gallifreyan ray gun, which us 70s kids were able to replay at our leisure and dub onto our own scrappy audio stories via the BBC Sound Effects LP.

Roger Murray-Leach's Sets
Always one of the original series' most imagination-blessed designers, he skilfully camoflages the story's Television Centre location by building a multi-tiered set that suggests scale on a pocket money budget and a recording space smaller than Matt Smith's trailer. (Probably)
John Dawson and Michael Bilton's Nattering Time Lords

The Statler and Waldorf (or Ena Sharples and Minnie Caldwell) of Time Lord high society, these were exactly the kind of doddery, gossipy Gallifreyans that had the DWAS frothing. But as underused as they are, they're up there with the best of Robert Holmes's Who pairings.

Runcible
Hugh Walters's fruit-flavoured TV correspondent. Give that man a BBC3 show to present.
Episode Three

An episode so dizzyingly surreal, it makes Luis Buñuel look like Jimmy McGovern. Who cares if the Matrix looks like a Dorset quarry when you've got such such amazing, nightmare-inducing shots as the Doctor reflected as a clown and that staggering First World War soldier? So good, they tried it again with The Ultimate Foe, though that was wank.
Steve O'Brien