Hello I will be traveling to Dublin for the Thanksgiving holiday. I would like any information regarding the 2 following hotels. I need to stay at a Marriott hotel, the 2 I am considering are The Shelbourne and The College Green Hotel( formerly a Westin). Which is a better location for walking and sightseeing? First time to Dublin would like to explore pubs, sights, maybe Christmas markets? Any information would be greatly appreciated. Thank you.

While there are many Dublin experts here on the forum who can help, I'll just note that I really enjoyed visiting the Shelbourne when we visited Dublin. I didn't stay there but we made sure to enjoy their afternoon tea (this was during the pre-Christmas season). I thought the location was perfect. Since both are Autograph Collection members, Marriott properties, which you need , I'd just add that the Shelbourne gets much high reviews on booking.com and a 9.0 from The Telegraph. I thought it was a classic, historic, grande dame hotel, a step back in time, one that I wish we could return to at some point.

You might want to peruse this trip report by denisea, as she stayed very happily at the Sherbourne.
Incredible, Impeccable Ireland...first trip to the Emerald Isle

DH and I stayed at the (former) Westin for our daughter's graduation from TCD in October 2023. The location is ideal for sightseeing; and our room was nicely appointed. Not sure about Christmas markets in late November, but there will certainly be attractions within easy walking distance.