Best plain/greek yogurt? The thicker and more sour, the better.

Anywhere in the valley to get really good plain yogurt? I'm specifically after sour thick yogurt like they have in Greece or other mediterranean countries. Everything I've tried from a few grocery stores doesn't quite do it (greek yogurt or otherwise).

Avalon Plain - good flavour, but could be more sour. Not thick. Nice that it's available in large tubs.

Astro Balkan Style - also decent good flavour, but not thick either. Usually pretty expensive.

Shepherd Gourmet Dairy Skyr Plain 0% - Super thick! Not bad flavour, but I want it more sour! Most expensive option so far.

A bunch of greek yogurts I've tried I didn't like the flavour of, so not mentioned here.