It depends on your budget. I highly recommend contacting the hotel in advance to discuss the accessibility conditions you require because some are labeled as accessible when they are not completely.
If you are looking for a 5-star hotel the Four Seasons Resort at Papagayo Peninsula, guarantees a luxury vacation with many accessible rooms. Flat access, ramps, accessible bathrooms, a pool lift elevator, access to the beach and a beach wheelchair. Here you can enjoy the beach, do paddleboard, kayak, and scuba dive, besides all the regular hotel amenities.
Hotel Mangaby, in Playa Hermosa is a little hotel with a reasonable price, flat access from the parking to the reception office, rooms, and the restaurant. The pool has a ramp to get into it. The rooms are confortable enough with wide doors but the bathrooms have a low toilet with no grab bars and the shower has sliding glass doors that make it difficult to access.
In front of Mangaby, there is Villa Huetares Hotel, which has very similar accessible conditions and a restaurant called Coco Víquez, with a very national menu and excellent prices. Both hotels are very close to Playa Hermosa beach.
Hotel Isolina, located at Playa Potrero, also has flat access from the parking to the reception, accessible rooms, and access to the restaurant. You can get to the pool area using a ramp, but the pool itself doesn’t have wheelchair access. The rooms have wide doors, but the bathrooms lack maneuvering space.