Hotel recommendations for Oxford?

You might try either the Old Bank or the Parsonage. They are owned by the same people. The Old Bank is right in the city center.
We stayed at the Parsonage (back in 2015 I think) and it was very comfortable.

I stayed at the Marriott Courtyard City Center in April of this year and really liked the location. The hotel, of course, was nice, just like most Marriotts, and the location was a quick 5 minute walk to/from the train station. One nice feature, though, was that the area was relatively quiet. You head out of the hotel then walk along a lovely canal that crosses over on Quaking Bridge towards the city center. It was a very pretty area, and there is some beautiful architecture and cool shops along the way.

It was also very close to the Glouchester market, and the bus station for the Airline Bus (if you plan on going directly to or from Heathrow). It may not be applicable, but just saying... :-)

I paid with points so can't speak to the price, but I did enjoy my stay here very much.

Thank you both, Stacy and Mardee!

I will look at the Old Bank and the Parsonage.

The bus to Heathrow might be a nice benefit; we're still deciding whether to go to Windsor for the final day of our trip.

We would like to be an easy walk to the train station as we plan to use trains to get to the Cotswolds (Moreton-in-Marsh) and Bath.

I would not stay in Oxford to do a day trip to Bath, if that's what you're indicating here. I'd move to Bath and stay in a hotel there for 2 nights.

Oxford is perfect for a day trip to Moreton-in-Marsh and the Cotswolds. I assume you will be catching the GoCotswolds tour from Moreton-in-Marsh....good choice.

I would count on (at least) 3 nights in Oxford. One day for the trip to the Cotswolds. One day devoted to walking around seeing Oxford plus possibly a trip to Blenheim Palace.

Note: I noticed that someone already provided you the information on your other thread about how to take the bus from Oxford to Blenheim Palace.

Two nights staying in Bath will allow you to properly see Bath.

You can see Stonehenge on a (Mad Max) day tour from Bath if you wish.

Back to your original question
Premier Inn Oxford City Centre (Westgate) hotel is a good budget option for Oxford.

Is The Buttery a good place to stay?

srepoley, you might want to start your own thread to ask this question, rather than piggyback on another member's thread. That way you'll get a response via email rather than the OP (original poster).