I'll just list the most commonly run decks I've seen between 2400 and 2500, one per faction. Admittedly, some decks are very annoying, but quite binary (have very good matchups and very bad ones) such as cultists and reavers. Those I won't list at the moment.
If you have other meta deck that you wanna nerf, comment it below
Edit: you can see in the comments how each player has a very different experience on what is too common, too boring and too OP. This is why discussions like this are informative.
Edit2: there seems to be a clear difference between matchups that players hate to have, and matchups that feel unfair/unbeatable. I personally, don't feel that playing against Enslave 6 is that oppressive and I have a winrate of at least 50/50 against them.
Source: https://www.reddit.com/r/gwent/comments/11gxzrj/with_patchday_a_couple_days_away_which_current/