Try Mill Pond in Dorchester for Largemouth and Pike. A few good accessible spots on Thames in London include: Below the weir at Richmond street bridge near Labatt Brewery, the forks of the thames downtown, the lower reaches of springbank park, and vauxhall park in the east end, just to name a few
Try bread (surface or bottom) if you want to change it up and catch the over-abundant supply of large Carp...mostly smallmouth come out of the Thames though while spinning, tons in the 0.5 - 1 lb range...but you never know what you're gonna catch on the river.
walleye, tiger muskie, gar pike, northern pike, chain pickerel, speckled trout, channel and black bullhead catfish, all sorts of large suckerfish, freshwater drum...just to name some of the bigger species i've caught or seen caught IN London