I was very lucky to find tranquil Lenwade in Henley-on-Thames. I stayed every week (and some weekends!) for 4 nights for 18 months (2011 to 2013) due to work.
Located just a lovely short walk from Henley town centre and very handily located to Heathrow and motorways. The house and gardens are superb and bedrooms are lovely, very clean & fantastically maintained. Good selection of TV channels and free WiFi in room too. Breakfast was amazing with a choice of everything - I recommend the cooked English Breakfast which is to die for. The hosts Jacquie and John were wonderful and did everything they could for me personally and all other guests to make this a very happy, relaxed and friendly B&B to stay in.
i advise you book as early as possible as Lenwade was very popular - on occasion due to late(ish) date notification on my part, Lenwade was full and I had to stay at various other hotels/B&B's. These were not as good as Lenwade.