My favourite rivers in Ireland would have to be the Flesk or the Source of the Liffey. Unfortunately I haven't gotten to paddle either for ages. As for outside ireland it would have to be Fallock, amazing river from start to finish with an incredible waterfall at the start to get you going.
But behind them all I'd have to say I love the Liffey becauce thats where I learned to paddle.
Add them to the list.
Bill
PS sorry to hear about the shoulder Sara.