Since people are posting photos of 'bleak' housing projects in US cities, and generally ragging on modernism and Corbusian towers in the park, I think it's worth saying that here in London, modernism and brutalism produced some fantastic public housing and some of the best British architecture of the twentieth century. There are plenty of awful council estates... the majority of them are awful, frankly. But there are some pretty nice ones, and you'd have to pay a lot of money to live in some of these today.
Alton West:
Trellick Tower
Brownfield Estate
Bevin Court
Dawson Heights
Andover Estate
The Brunswick Centre
Whittington Estate
World's End Estate
Lillington Gardens
Fleet Road Estate
Alexandra Road Estate
Keeling House
Thamesmead
Thamesmead
Broadwater Farm
Not exactly a council estate, but close enough to merit honorable mention:
The Barbican