Ready made shakes - UFit, Huel, Huel Black. More for days when my appetite is super low but I need to eat.
Clear whey powder, mixed with water - MyProtein, Foodspring. Daily, to make up protein intake. The MyProtein ones come in loads of different fruit flavours and you can get sample packs to try them out.
Electrolytes - Phizz, daily, lots of different flavours; Liquid IV in the cupboard for the very occasional day (rare now) when I forget to drink or eat enough.