I have been to Wychwood twice and am going again this year. It is the most child friendly festival.
The campsite is lovely (in the middle of cheltenham racecourse),
you can drive onto the site, though you then put your car in the carpark after unloading,
the festival area is not too big and
there is loads laid on for kids, circusy stuff, craft tents, a childrens book festival.
Access to hot running water and flush loos is a big bonus and there are soo many small kids there. my youngest was 5 the first time I went and he just ran feral all weekend making friends and roaming around.
Not many big names but wide and eclectic range of bands and it is easy to talk to the bands if you want to find out more.
I'm not single but DH would rather have hsi teeth pulled so I always just take the kids. Would be nice to meet other MNs