There's multiple builds that can clear really high solo GR for next patch with all the buffs. Many can do 110+ with decent para. As for the "highest" it's hard to know. Cause the ptr has undergone many iterations this time round, with multiple ptr leader board wipes and such. A strong contender will probs still be bloodlance necro which can do like 118s right? It's hard to fully compare where everything lines up because not everyone has the time to properly push on ptr, or maybe they don't even want to show the build cause they have some secret strat. The highest I have seen is a Korean streamer attempting a 127 with dmo wiz. He was close to downing the rift with almost enough time to kill the rg. Keep in mind he has 5.5kpara, 9mil sheet dmg, and he's Korean. With his para and skillset he'd probs push levels beyond the rest of us mere mortals with any build he focused on
Edit: I misread and thought you wrote "best build" singular, not plural haha. Oh well I'll let my reply stand as is.
Good day mates i need your help about picking class for S12 i thinking about hota /ik barbar or necro pestilence BL rly dont know what will be in meta necro sure i guess but i dont wanna happend if i push gr with ppl they dont pick me coz im hota barbar or something like that .. So can u help me decide pls?
there's so many viable builds for each class, if you had to pick a class that would be better in solo push you would end up with better information than wanting to pick a build for this reason.
class-wise there's not too much difference, but necro lancer is still slightly on top and wizard with its numerous top100 level builds edge out other classes due to how viable they are in group with different roles both speedparagonfarm and push (lancer/boneringer push, rathma farm or 2-3man push, znec for same comps as rathma, wizard support for either comp or dps that is a good alternative to WD in push and makes a more standard comp almost as good as rathma at paragon speedfarm)
it may not exactly be meta, but everything capable of gr 100 solo is capable in some form or fashion of getting gr 105-110 in 4man if not higher with the right type of group setup. scout/buff support, grouping/buff support, and 2 dps can have lots of variation this patch.
for example just in casual speed grs, zmonk + zbarb with some globe generation + rashameteor 3mil damage and bad deathwish + me n6m4 dh 3mil damage have consistently done 95s in 5-6min. thats about what we did at same gear lvl last season prior to getting 3.5mil damage on rathmas to push 111 with znec/zdh/2rathma. you can do much higher than in the past with not exactly meta specs, it just might not hit leaderboard unless you really hit the paragon farm and setup the group to be most inclusive for your spec.