Are you planning to live in the city itself or one of the surrounding towns?
For the city itself bear in mind that the schools are very full and for primary it may mean having to accept anywhere that has a place.
For secondaries Cherwell has always been the desirable one but that comes with a catch in terms of property prices. You can't rely on just being in catchment either - every year a lot of kids living in catchment are turned away. Of the other schools, people I know with kids at Spires speak well of it but historically it takes a lot of disadvantaged kids so headline results not so good. Cheney is very up and down and I would say it was a bit chancy.
Personally if I was to live in the city I'd go for a property in Botley and make sure I was in catchment for Matthew Arnold - always had a very good reputation - you can also live in Kennington and Cumnor to get in here (although the bus service from Kennington always seems to be under threat so bear that in mind.). Bartholomew School in Eynsham is also accessible from Botley.
Again the secondaries are very full so if you buy a house for your intended secondary and it the doesn't seem right for your kid you probably won't be able to get in anywhere else.
If you're happy to live a few miles outside the city Eynsham is a good choice - the secondary there has a decent reputation but you've also got the choice of two good schools in Witney which are easily accessible - frequent buses. It's one of the few places in Oxfordshire where you may actually get a choice!
If you don't mind living anywhere in Oxfordshire - Thame is a good choice - a very good comprehensive and you can also try for the Bucks grammars if grammars are your thing. You can't really go wrong with a lot of the one school owns - Wallingford, Henley, Woodstock are all safe choices.
Unfortunately can't give you my own DD's experience as she goes to Didcot Girls - fab state school but not much use to you!
Hope that's useful - PM if you want more details!
Best wishes.