antigua, st. thomas or turks & Cacos
 

looking to relax on the beach with a drink, nightlife, horseback riding etc. shopping is not important.

Drinks are available on all three islands. Skip the T&C's if you are seeking nightlife. When you say "Turks & Caicos I assume you mean Providenciales' Grace Bay (where 98% of the resorts in that island chain are located). If so, the beach there is 11+ miles long with fine white sand and calm bright torquoise blue waters with little natural vegetation. Antigua has more but not necessarily better beaches than St. Thomas. Beaches on both those islands are smaller than you'll find on Provo but they are more picturesque. I can't comment on horseback ridding other than to say you'll probably find it somewhere on both St. Thomas and Antigua - not sure if you'd find horseback riding anywhere in the T&C's.

A traveller is right.
I would add that T&C is much much more relaxing and tranquil than STT with much more beautiful beaches but with far less nightlife and far less visual scenery away from the resorts than STT. T&C has less nightlife than almost any island in the caribbean, it's all about the beaches there, the best in the caribbean but if you seek nightlife I would suggest ST Martin or Aruba, both offer very good nightlife, casino's and bars/clubs.

forgot to add that I have never been to Antigua but relatives that travel throughout the caribbean just returned, stayed at Jolly beach AI and enjoyed the resort and said it was visually attractive with the mountains in the backround and very nice beaches but commented that it was not a clean island, lots of litter especially in ST Johns, nigthlife/activities mainly at the various all inclusive resorts in Antigua.

I love Antigua and recommend it. Dickenson Bay has everything: Bars AND restaurants. Go to Sneaky Pete`s, get a drink and watch the sun go down. It will take your breath away.

Love Antigua !
I second Sneaky Pete's in Antigua....beautiful!
We stayed at Sandals and loved it. Loved the champagne on our balcony every night as we discussed dinner plans. Didn't horseback but friends we met did. (She fell off though and had to take it easy after that, thus not placing in the Caribbean dance contest !) We went waterskiing daily...well tried, and enjoyed the nightly entertainment right at the resort. We went into town once...it was OK...took some nice tours and ate off resort some.
We have not been to St. Thomas. We found T&C very quiet but pretty. We like Antigua the best.