At $2 to the pound until quite recently London seemed like an expensive and crowded tourist option for many Americans, Europeans and Australians. But the credit crunch has seen to that and London is suddenly 20% cheaper. And now the summer is over the crowds have dissipated and London is left with world-class attractions and plenty of beds, seats and chairs for visitors.

What?s on in the West End?

The four top shows to see right now are all brilliant and well worth the investment.

The 39 Steps has just past its second birthday at the Criterion and has just announced that its run has been extended yet again. The play is adapted from the novel by nineteenth century novelist John Buchan and the 1935 film of the book by Alfred Hitchcock. The play is a comedic spoof-thriller about Richard Hannay a London gentleman who is drawn into a foreign plot and ends up on the run himself after a woman is found murdered in his flat. I saw the original London show at the Tricycle before it opened at the Criterion and it is heartily recommended. The production won "Best New Comedy" at the Olivier Awards in 2006. A Broadway spin-off won two Tony Awards this year.

I still the recall the excitement I felt when I first saw Grease on screen with Olivia Newton John and John Travolta and I can't believe that was in 1978. Still the songs have stood the test of time and the story still uplifts. One of the classics now, this musical is a very strong revival with a great cast and outstanding choreography. A fantastic family musical for those bringing kids and teenagers to London.

Hamlet. Shakespeare?s signature tragedy is on at the edgy Donmar Warehouse with Jude Law as Hamlet and direction by Kenneth Banagh. With this quality of talent the production promises to be impossible to miss. The King of Denmark, Hamlet?s father, is murdered and Prince Hamlet is overcome with grief and resolves to avenge his father?s death. The consequences for Hamlet, his family and his Kingdom are devastating.

Mamma Mia! You have seen the film. Now see the stage show which inspired the ABBA revival. You will be singing and dancing in the aisles. It is unforgettable. The stage show was written by English author Catherine Johnson, and the project's originator, Judy Craymer while Bj?rn Ulvaeus and Benny Andersson from ABBA worked on the music for the show. The result is a stunning feel-good show with romance, comedy and incredible music. The story is the same as the film ? a young woman, Sophie, invites three men she suspects may be her father to her wedding, but without telling her mother, Donna. The story is a search for identity which leads to unexpected romance for Donna as love is rediscovered.

Before or after the show have a meal at one of the literally hundreds of fabulous restaurants and cafes in Soho, Covent Garden and around Leicester Square. The food in London is now better than ever thanks to the national rediscovery of cooking led by celebrity chefs.

Transport to the West End is easy with tube stations at Covent Garden, Leicester Square and Holborn close-by and hosts of buses and cabs to take you back to your hotel or rented accommodation. For those interested in getting a deal, many theatres offer cheaper tickets same day. Details are on the theatre websites.