We split our time between The Springs Resort in La Fortuna/Aronel (amazing, but not all inclusive although food was wonderful and reasonable) then at Dreams Las Mareas, which was all-inclusive but the food was awful, so I wouldn’t recommend it.
We stayed at a Riu all-inclusive resort in playa del Carmen and really enjoyed it. We bought ours off of groupon and got a steal that even included air fare. You could check there.