Okay, this is actually a pretty big convo.
When we talk about water filers, we could talk about for short trips/overnights, we could talk about longer stints in the backcountry or for larger groups, or we could talk about emergency water filtration that you keep in your "just in case" stores at home.
I'll leave it open-ended because there are so many varieties with so many different intended purposes. Personally, my go to for any outdoor adventure is MSR. I had used a Trailshot for years and absolutely loved it, and I eventually ended up upgrading to the MSR Miniworks EX. It's a bit bulky, but I haven't had any issues with it.
What water filtration system do you use? Do you have a favorite??