We did La Fortuna, then Monteverde, then Playa Hermosa. It was probably my most favourite ever holiday.
We hired a tour guides to take us on guided walks quite often, and we hired drivers to drive us long distances. It sounds expensive but there were 6 of us and it worked out really well. The drives are long and windy - we took a LOT of Dramamine with us. Everyone survived all the drives. Some of the roads are terrible.
My favourite place was Selvatura in Monteverde. We'd already been ziplining at La Fortuna, so we did pretty much everything else on offer there - the butterfly garden, suspension bridges walk, hummingbird garden, reptile and amphibian museum. The whole day was just magical.
We also hired a guide to take us birdwatching in Monteverde, and we saw Resplendant Quetzals and lots of other beautiful birds, and it was just a gorgeous walk.
At La Fortuna, I really enjoyed the 3k zipwire, and a couple of the fancy hotels where you can pay to use the waterslides into the thermal waters. I'll try and post links.
Yes - I think the Royal Corin was one of them. My kids adored it.
If you go to the Tabacon hot springs I'd say go in the day rather than at night. Mainly because there are some really massive beetles wandering around, and at night there's a good chance you'd step on one.