Skull, Batman or Devil Island
Batman Island is a really cool feature of the center map. It looks cool and has the best obsidian deposits on the map. In addition to the obsidian there is also a ton of metal and a good amount of crystal. Those two resources are pretty easy to come by in other places though. In order to get some obsidian you are going to need at least a raft to get there, The bottom teir of the island can be walked up from the raft and into the mouth. There is a small amount of obsidian their for the taking. I've only encountered a few bats there, so it is relatively safe. I believe the next tier of the island is only accessable with a flyer and it as well as the very top hold the most obsidian. It is easy to weigh down and Argentavis with the amount found on the top two tiers. There are a few more bad guys to deal with there, so be prepared for Titian Boas, Arthropluera, Spiders, Scorpions etc., but it isn't too terrible.
At the top of the volcanoes there is some obsidian and lots of metal, but it is a dangerous place. The few ponds on the island have quite a lot of silica pearls and some oil, but are filled with Mega Piranha. The shore of the pond also have pretty much every terrible creature waiting to gobble you up. If you have friends with you or just want the challenge it can be a good place to get pearls and oil. I tried it and lived, but I won't ever do it again.
Penguin Pond/Iceberg Lake
Way on the eastern side of the map below the snowy mountain and right next to the obelisk is a lake with a river flowing out of it. In the middle of that lake is a big iceberg. The iceberg has a small population of , Kairuku (penguins) which are a good source of organic polymer. The iceberg is also dotted with oil and metal nodes. The iceberg is a fairly peaceful place most of the time, but Spinos can and do visit the levels even with the lake.
Snowy Mountain North and South
The snowy mountain tops are loaded with oil and metal nodes for the taking. These are probably the only nodes that can be reached without swimming and flying. If you chase oil resources here bring your fur armor to protect you from the cold. There are also plenty of dire wolves to ruin your day, so keep you eyes peeled, this is still Ark Survival Evolved.