Hi,
The only way I can describe the places here is from experience both as a holiday maker and someone who lives here.
1) Caleta de Fuste is a man made purpose built resort. It has a couple of 5 star hotels because there are 2 championship golf courses . It has a nice harbour area with an aquarium and there is plenty to do, especially for families. The promenade is a nice walk and the beach is clean and tidy, but again man made. I struggle to find decent food in the resort at the prices I pay in Correlejo.
2) Jandia and Costa Calma. Lovely beaches but distinctly lacking in soul. Not many places to sit nd have a coffee and watch the world go by. Great if you like good quality all-inclusive hotels and surfing, but not much more besides. They are closer to the La Latija zoo and botanical gardens, but over an hour and a half from the airport. I personally find nothing great about either and certainly wouldn't stay there unless I wanted to go AI for 2 weeks and not move from my hotel.
3)Correlejo in my opinion is the most Spanish of the major resorts because Spanish families live and work here. If you ignore the main street into the resort and walk down to the harbour area, you will find nice restaurants serving good quality inexpensive food. We have one or 2 quaint streets, but the old town area is a little bit scruffy for some. It's usual for Spain to find holes in the pavement and patches of ground that seem to serve no purpose. The council spends the money on keeping the main tourist areas looking nice and this is what they do. You can walk right along the harbour, stopping for a coffee, overlooking the town beach and wander on a bit further, watch the ferry arriving from Lanzarote every hour etc. We have the waterpark here, you can find nightlife in the Atlantico Centre if you want it and a quiet bar in a back street if you don't.
We also have 6km of gorgeous sand dunes just outside of town, where you might spot the odd nudist (they won't hurt you if you ignore them)
The most authentic town here is Betancuria, which is nice for a visit, but not enough to keep you occupied for any length of time. Puerto Del Rosario, our capital, has a nice harbour and a few decent shops, but is a working town and not really a tourist place.
The weather is normally very good, saying that we have just had a dodgy spell which is most unusual for this time of year. The food and wine on the island is excellent, fish and shellfish are especially good as are the local goats cheeses. You really need to get out and about, so try to hire a car or go on one of the excursions I have detailed above in the "What is there to do?" thread. There is a market in all of the major resorts at least once a week, this is a craft market and not a food market, most of the stall holders are African. This means that you rarely get hassled in restaurants at night by looky looky men. There are at least 10 museums here on the island and you can get information on them by looking at the free tourist guides you can pick up in most resorts. People complain that there is very little to do here, you can do as little or as much as you want, but you need to go out of the resorts for a lot of it.