I'm late to this thread but the Thames has been a feature running through most of my life. I grew up in Richmond-on-Thames, learnt to row at the age of 13 on the Thames at Putney (and rowed on it for the next 30 odd years), studied in Oxford with the Thames (known locally as the Isis) at the far end of the meadow, moved back to London and after a few years got a job at an oil refinery on the Thames estuary, then after a spell overseas bought a house round the corner from the Thames, to make it easy to go rowing.
But there is also a place in my heart for the Clyde, - or strictly speaking the Firth of Clyde, where I spent my childhood summer holidays, the big treat being to sail on this vessel:
(which I was able to do once again a couple of weeks ago, amazingly, thanks to the dedicated work of the Paddle Steamer Preservation Society).
Whenever I travel I'm interested in the rivers. Crossing the Tweed or the Ribble, staying beside the Lune in Lancaster, Looking out for la Rance when driving across Brittany, trying to make out the names of the various distributaries of the Rhine (or Rijn) when we lived in The Hague......for some reason the rivers seem particularly special features of the geography.