Parking & access is the problem.
Donnington is stuffed with bream & roach (odd tench, odd carp, odd chub) but 1,000,000 other people all out at the same time !! Folly upstream can also be a pain but good fishing if you can put up with it all with the early morning Hookers and various addicts. Good chub & perch at Osney and at The Watermans. Big chub in the Channel. The other way Iffley has a good head of fish but lots of moored boats so not many swims now. The Spinney at Kennington is often overlooked and the main part of Kennington means parking somewhere in Kennington. Then you have Kennington's old water down to Sandford lock (Fiddlers Elbow as well). Sandford car park (It'll be flooded now though) gets you opposite LIttlemore's water and on down through AOAA water to Radley.