Whats the best car for use in UA?

Yes, Lada Niva could be one of the variants, but without enough level of comfort.
So any kind of SUV would be a relevant car considering the condition of local roads.

It is worth paying attention to reliable cars that are not afraid of dirt, water, and potholes on roads with high ground clearance. I would consider models like Chevrolet Niva, Suzuki Grand Vitara, UAZ Patriot, Volkswagen Amarok. Volkswagen Polo has not the largest clearance among the cars of its brand but is still perfect for Ukrainian roads.

If you ever traveling Ukraine and need your car to get fixed, I recommend you this service [link moderated]. You just choose whatever city you are in and find a suitable service station.

Interesting that you recommend pick ups and a Polo? What about the Polo is it a good choice? Why?