Other Category 5 Marriott hotels in Thailand in no particular order:
Casa de La Flora, Khao Lak, Phang Nga, a Member of Design Hotels
Renaissance Koh Samui Resort & Spa
Le Méridien Koh Samui Resort & Spa
Sheraton Samui Resort
Renaissance Pattaya Resort & Spa
JW Marriott Phuket Resort & Spa
Phuket Marriott Resort & Spa, Merlin Beach
Renaissance Phuket Resort & Spa
Le Méridien Phuket Beach Resort
Marriott's Mai Khao Beach - Phuket
Sheraton Hua Hin Pranburi Villas
JW Marriott Khao Lak Resort & Spa
Le Méridien Chiang Mai
Originally Posted by
CrazyInteg
OP has said twice that he/she is looking for beaches. Which areas would you recommend OP visit for beaches that are convenient to Bangkok?
"I'd like to spend some time on some nice beaches"
"Seems like we would just need to plan for a few full-day beach trips from Bangkok instead"
You gave your opinion and I provided a different advice. The more divergent views, the better informed decision the OP will make.