Brita is the most popular here as well. I have a water jug from them. While the tap water is perfectly drinkable here I like to filter the water I use for tea and coffee. The tea tastes better and the coffee machine gets less limescale.

Also worth mentioning BWT (Austrian brand) home filtering systems and water filter manufacturers. My sister has on of them fancy kitchen taps with built-in filtered water option and it uses a big BWT filter.