i built my base on hidden lake (north east corner of the map close to carnivore island). it amazing, i have close access to three mountains, so metal crystal and some obsidian, carnivore island is a short fly away, so alpha killing, beacon hunting, and rexes, scorpions, and argies. the ocean is also very close, so oil and silica pearls are relatively easy to get to (there are electric eels and possible alpha sea creatures tho, so have to be careful). also drops spawn in there, even with my base there, including purples and reds.
all in all, it's a nice place to live