Ascended Gear
Dungeon/Fractal content you want as much Assassin/Zerk as you can get, because the content is designed to allow you to survive without the passive defenses by utilizing your active ones (dodge/block/blind/reflect) So I’d go with Assassin/zerk accessories/weapons.
Celestial will get you a bit more defense and some condi and that simply doesn’t translate into dungeon/fractal play very well.
WvW there are different builds utilized for different type of fighting. And PVP your gear doesn’t matter.
I rune full celestial ascended across the board and I find it rather ideal. Either way, they are the most time consuming to make, the others are rather quick and easy in my opinion, so you might as well make it all celestial to start, and then go from there.
https://www.youtube.com/watch?v=6q3em9s5I4c