It's worth noting that the Circle
Line platforms are probably the oldest underground
railway stations in the world, being built in 1863 with the Metropolitan Railway
(the world's first subway
The station is more or less in its original condition, with a traditional European station roof covering only about two thirds of the platform, the rest remaining open to the air, so as to allow smoke from the original steam locomotives to escape.
As for the main railway station, it has been seriously fixed up by Railtrack in the last several years, and is now extremely spartan and clean. There are no trash bins for obvious reasons, but there is a severe shortage of benches. At the rear of the station is a recent addition of a miniature shopping mall called The Lawn, containing a Sainsbury's Local, a Yo! Sushi, and various other miniature versions of popular high street shops. There is also a huge airline check-in desk for American Airlines and the Star Alliance, among others.
The station has also been electrified with catenary in recent years, mostly for the benefit of the Heathrow Express trains, although the wires outside the station also serve the North Pole depot for the Eurostar trains. Quite why the entire line to Bristol, South Wales and Cornwall was never electrified like the ECML and WCML remains a mystery.
The other companies serving Paddington are First Great Western, who run Class 43 High Speed diesel-electric trains to the West, and Thames Trains who run much smaller DMU trains to Reading and a few points past.
The station has 12 platforms. Numbers 9-12 are intended mostly for the commuter trains, or the Heathrow Express.
There is a statue of Mr Brunel next to Platform One at the exit from the taxi/drop-off area. There was also a Paddington Bear display many years ago, but this has since been greatly reduced to a life-sized stuffed bear next to the luggage storage shop on Platform Twelve, and a rather shoddy mural visible only from the east end of the Hammersmith and City platform.
Edit 15/12/04: Thames Trains have lost their franchise to First Great Western, who now call the services 'First Great Western link'. There is also a large bronze statue of Paddington Bear next to the escalators in The Lawn, and there's a pub upstairs that sell dodgy jacket potatoes (they didn't agree with the missus)