The Philanthropist, Donmar, London<br></br> Romance, Almeida, London<br></br> On the Ceiling, Garrick, London

While David Grindley's production is scrupulously in period, the piece stands the test of time in its portrayal of moral weakness, decadence and people's unsettling mix of caring and disengagement. Developing into an intimate study of a failing relationship and loneliness, The Philanthropist also has the ring of autobiographical truth about it - something like Stoppard's Jumpers-going-on-The Real Thing.

The tragicomic sharpness is intensified by Grindley's fine-tuned cast. Moreover, Russell Beale has always excelled at playing angst-ridden intellectuals but here - looking unforgettably like a woebegone hedgehog when subjected to the nympho's head-massage - his desperately funny performance defies superlatives. He combines witty timing with deep pain, so you can't see the joins. Every apologetic flinch appears to emanate from his core. Simultaneously, his character intriguingly has some kind of hole in the middle, like a touch of autism - potentially suicidal yet also automatically returning to his books and, perhaps because of that, surviving. Danny Webb is riveting too as his chummy but self-interested colleague, Donald, and Anna Madeley's initially self-conscious Celia becomes increasingly touching. All in all, terrific.

The same cannot be said for Romance, David Mamet's new Absurdist courtroom farce starring John Mahoney from Frasier as a stupendously gaga, pill-popping judge. Directed by Lindsay Posner, this is sporadically hilarious and sometimes fascinatingly fractured, linguistically, but more often it's wearisome, satirically unsubtle and curiously puerile. Mamet is knowingly wrecking the old tension-ratcheting genre of cross-questioning and moral grandstanding, as the furious little prosecutor (Nicholas Woodeson) is constantly interrupted by His Honour's blathering. The row between the defendant (Nigel Lindsay) and his attorney (Colin Stinton) is a fabulously savage eruption of un-PC bigotry - Jewish v Christian. However, Paul Ready as Woodeson's fuming, queeny boyfriend is a dreadful cliché and Mahoney, though having fun, is too endearing to disturb. The cod-climax - where a promised solution to the Middle East crisis dwindles into burbled nonsense - raises a nihilistic laugh before it seems merely flippant.

Nigel Planer's first play also comes over as an inflated sketch, and there's something ironically topsy-turvy here. Seemingly rooting for the little guys, On The Ceiling focuses on two lowly Renaissance craftsman toiling away thanklessly on the Sistine Chapel, spraying colourful expletives around about the grandiose incompetent Michelangelo. Yet if it weren't for Planer's own star status, this show itself would, surely, never be in the West End.

He patently wants this to be Rosencrantz and Guildenstern are Dead Mark II at the same time as trying to get serious, rehashing Amadeus's themes of artistic jealousy and genius manqué. The evening is actually most interesting as a lesson in fresco techniques. Ralf Little is disappointingly lame as the dim apprentice, Loti. Ron Cook, as the frustrated wannabe Lapo, has determined charisma and a nice line in clowning. He's the best thing by a long chalk in a rickety play.

k.bassett@independent.co.uk

'The Philanthropist': to 15 Oct, 0870 060 6624; 'Romance': to 22 Oct, 020 7359 4404; 'On The Ceiling': to 31 Dec, 0870 890 1104