I'm a current windsor resident, the catered hall next to park bar. While I would recommend this hall to everyone because of it's insanely friendly and social atmosphere (living with 20+ people in a corridor and eating in groups down at park bar every single day really helps) , I understand not everyone is down for this. I would still suggest going for another park group hall, it has such a central location. St. Georges, sherfield and benyon are off-campus and depending on your course it could become an insane hassle.
I recommend Mccombie as it is another very social hall with en-suites, for fresher's they're also paired up with Windsor so you get the chance to meet a lot more people outside of your hall the first weeks. I will also (most likely) be one of your JCR if you choose to live here and I will do everything I can to help make your first year memorable! Shameless hall promotion