We recommend visiting every single Lost Ark Gold island eventually, however, you may want to start with the simplest and most rewarding ones first. The islands listed here can be completed in a matter of minutes, very rewarding, filled with pandas and turtles, and are also part of major questlines.
The Lonely Island. We've talked about him a few times by now and for the sake of keeping this list complete Make sure you visit Opher on The Lonely Island. It is possible to exchange you Island Souls for awesome turtle skins and other. You can also receive an free Island Soul by simply talking to Opher.
Golden Wave Island. It's an island full of loot chests. Visit if you're looking for lots of stuff (Pirate coins, cards and green engravings) at a fraction of the cost.
Panda Island. Be sure to avoid this island if your a fan of pandas. There's also an incredibly short blue and purple questline that rewards you with plenty of Silver, Weapon and Armor Crystals, Harmony Shards and Harmony Leap
Turtle Island. When you complete the whole questline, it doesn't just award players with Island Soul and valuable Jewel Coral as well as the Turtle mount. You can also pick its color.
Serenity Island. Within a couple of minutes it will give you a nice stack of Weapon and Armor Crystals. Also, you'll acquire a Skill Potion through your Stone of Power quest, which will require a rerun of cheapest Lost Ark Gold an earlier dungeon, the Morai Ruins and Tortoyk's Heart Dungeons.