Which European country gives fastest permanent residency easily?

Which European country, would you say, offers the quickest route to obtaining permanent residency, and what makes it relatively easy to achieve? Is it a country with lenient immigration policies, or perhaps one that has a straightforward application process? Could it be a nation that values skilled workers and entrepreneurs, or one that favors foreign investment? In terms of cultural integration and language barriers, how does this country fare? Is it a popular destination for expatriates, and what are the key attractions that draw people to it? Could you also elaborate on any specific requirements or conditions that need to be met in order to secure permanent residency in this country?