Palau
Palau is the dive destination vacation. You really shouldn't be going to Palau unless you really want to be spending your time underwater. The walls are ridiculously vertical. I mean, *nothing* below you. Awesome. Drift dives are fantastic - you get to see a larger area underwater, and stop to explore what you want to, when you want to.
The soft corals here are unreal - everywhere - all colors - it's just so colorful underwater! Fishes everywhere too - and not to mention sharks! I was expecting more different sharks - we only saw Grey reef sharks and whitetip reef sharks - but we saw TONS. Blue corner was my favorite place to chill - but the best dives I have had were at Peleliu. Peleliu was epic. super clear water (150' viz) - strong currents, and just the most gorgeous blue you can imagine.
Topside was very quiet. Nothing really open after 8pm, and not too many food and nightlife options. My suggestion is to find a favorite watering hole/restaurant and stick with it. We drove around the island - but Koror really was all we needed to see. The dirt roads to the northwest were fun to get lost on though - make sure not to get lost after dark with no cell reception and out on a forgotten dirt road….
If you can afford it, the live aboard option is the way to go - and frankly, if you're traveling to Palau - you can afford it. If you stay extra days before or after, hit up the other charter companies which are also worthwhile.
OH! Almost all the wrecks in Palau are INSIDE the lagoon (didn't know that going there) so visibility is pretty low. I think the Chuyo Maru had about 20' viz while we were there, which added an odd eerie green to the wreck. Teshio Maru was probably my favorite wreck - huge, lots of areas to explore, and seeing the damage of a bomb on the ship really was mind-blowing. Helmet Wreck had about 40' Viz and Iro Maru had about 60' - but once you start wall diving, the visibility opens up substantially to over 100'.