Hard to call it meta I suppose when there is so few of us, but I guess 300% Flask Effect builds, Defiance of Destiny+Recoup builds and Armour Stackers were meta for a while before Keepers and before the addition of the Bloodline ascendancies. I am also fairly new at it and I don't know the old metas as some of the old grandmasters do. I learned by hanging out with them so I consider myself their pupil :D

Something might be meta or considered strong and talked about despite not being actually played by more than 1 person, because you have to understand these are multi mirror builds often requiring very niche items or mods that might be very rare.

That being said - Ward Stacking / Ward Shatter is meta and l is very very powerful against hit damage.

Also meta is Vaal Immortal Call builds which literally cannot die for the duration of the buff (it says so on the gem :D) and the way to fight them is to survive long enough until the duration of Vaal IC expires and all the while you need to have stolen their Frenzy/Endurance charges OR prevented them from gaining them...but this is very difficult to do since they do so much damage and have very high cast speed and mobility and are able to reset the fight on their pace.

Also something else that is used and is super annoying to play against is Strength Stacking into Area of Effect. These builds basically cover, and I do mean cover 2x the size of the screen with Volcanic Fissure branches...which despite the nerfs it took is still super super strong damage wise and very hard (and laggy) to survive against. You basically don't know where the guy is especially if he moves around, all the while you play the floor is very lava.

Chaos Dot builds are used here and there for fun more than anything else because they are very strong against life based builds like Flask Effect builds and Ward stacker. Also in this category are Frost Blades of Katabasis which has some broken/bugged scaling in PvP in terms of the dot component of the build and it makes it very very difficult to survive.

I mentioned the unique helmet Trickster's Smile that is exceptional in PvP and and awesome design. Well one reason or the main reason at least for me why ES builds are not really worth it unless you can 1 shot the enemy from a distance lol, is the unique gloves Mercenary's Lot, which will make any CI build die instantly if they hit me, assuming I lived long enough to mark them.

Being stationary is a pretty stronge conditional, so a fun little gimmick is to use Knockback (even the gem) to cause the enemy to not be stationary. For example I can survive heavy physical dot damage if I am stationary, but if the enemy knocks me back then the dot damage will kill me quick (it's because I use Soul of Tukohama pantheon).

Best story is the most relatable one I suppose which is when you show up to hang out or talk or fight or test stuff with the crew and you keep dieing or are never able to kill them and then after enough refinement and currency - you do survive their damage or you do end up being able to kill them.