Some plays are game-changers. When Jonathan Harvey’s Beautiful Thing opened at the tiny Bush Theatre in 1993 the joy that radiated off the stage was ample affirmation that this tale of puppy love had changed the face of gay plays for ever. Gone was dreary soul searching; gone was guilt; gone was militancy. Instead, we got fun, laughter and real heart.

They’re back, and this time it’s Gorky.

In spite of a text that feels at times like Shakespeare by numbers, Andrew Hilton’s tightly-knit company has once again pulled off an evening of captivating theatre. As in other productions from Shakespeare at the Tobacco Factory, the casting is pitch-perfect and the acting first class, down to the star performance of a hilariously mournful black dog.

Or, The Lord and Lady Macbeth of the Seizième, as imagined by a bourgeois teenager who fancies himself to be Bougrelas, heir to the Polish throne. That's one way of looking at the concept so dazzlingly carried through by Declan Donnellan and Nick Ormerod with the French wing of their Cheek by Jowl Company.

The family can be a knot of hatred as well as a cradle of love. Rather late in this new play by Tanya Ronder comes a scene in which a separated husband and wife try to untangle this knot, and end up by tightening it. And this takes place around a table, which is silent witness to this epic tale which spans more than a century, and uses nine actors to create some 23 participants over six generations.

People sneer at musicals for endless reasons: they hate Broadway brashness, non-naturalistic lurches in and out of song, the sentimentality. One of the least acknowledged reasons, however, is because their plots – predictability plus songs – have zero tension. And you know what? Placed in the witness box, many a musical emerges guilty as accused. But the quietly astonishing Once is innocent of all those charges.

Anthony Neilson is the wild man of new writing. However, this reputation, which has been provoked by shock-fests such as Penetrator (1993) and Stitching (2002), belies the fact that some of his best work, such as The Wonderful World of Dissocia (2004), exudes a warm humanity and offbeat humour. But perhaps the most significant thing about some of his recent work has been his concern with process.

"And, to deal plainly, I fear I am not in my perfect mind." So speaks King Lear towards the end of his monumental journey of self-knowledge that has taken the mad monarch from the highest to the lowest reaches of human experience.

Unsurprisingly, it was an ambition long held and within the grasp of the actor Edward Petherbridge to play Lear, widely regarded as the summit of a classical thespian's career, when, in New Zealand to take on the part in 2007, he was struck down by not one but two strokes.

Ruth Ellis, the last woman to be hanged in Britain, is a cultural icon, the image of the peroxide blonde who spells big trouble. An influence on Diana Dors in the 1956 film Yield to the Night, she was played by Miranda Richardson in Dance with a Stranger in 1985. Last year, a new biography, Carol Anne Lee’s A Fine Day for a Hanging, was published. Now, playwright Amanda Whittington tracks down this fraught and troubling figure.

Molly Sweeney has been blind since early childhood. Supported by her understanding father, she has grown into a confident, independent woman. Then her new husband Frank and an ambitious ophthalmologist, Mr Rice, suggest that it might be possible to restore Molly's sight and she undergoes two operations. Partially sighted, she has to learn how to find her way in a mysterious new world where nothing is as she has experienced it. Her sense of herself is undermined, she loses her equilibrium and becomes confused in a mixture of memory and reality, seeing and not seeing.