London Waterloo is a very large terminus station located near the South Bank in London. You can see a wide range of Third Rail EMUs and some DMUs. These include classes 442, 444, 450, 170 & 159. Ticket inspectors check tickets, so you will need a platform ticket to access the platforms, however you can see numbers from the platform entrances. You can also see from a distance Waterloo International, and you can see some Eurostars! Waterloo station is well served by buses and trains. I strongly suggest you take the train or tube. There are a few fast food restaurants on the station, but if you have the time I suggest you take the short tube ride into Central London. Waterloo is on the Jubilee, Northern, Bakerloo and Waterloo & City Lines.

If you're not after the channel tunnel trains, then Clapham Jct has all the Waterloo traffic plus alot of the London Victoria units (incl Gatwick Express).

End of platforms for photo shots, and a never ending stream of traffic in and out every few minutes.