As of my last knowledge update in January 2022, I don't have real-time data or updates on specific internet service providers in Pakistan. However, I can provide you with the names of some major internet service providers in Pakistan that were known for providing reliable services. Keep in mind that the rankings and performance of these providers may change over time. Here are four well-known internet service providers in Pakistan:

1. PTCL (Pakistan Telecommunication Company Limited): PTCL is one of the largest and oldest telecommunications and internet service providers in Pakistan. They offer a range of internet packages for residential and business users.

2. Nayatel: Nayatel is known for providing high-speed broadband services with a focus on customer satisfaction. They offer fiber-to-the-home (FTTH) internet services in selected cities.

3. StormFiber: StormFiber is a fiber-optic broadband service that provides high-speed internet, HD television, and phone services. They have expanded their coverage in various cities across Pakistan.

4. TransWorld: TransWorld is another provider offering high-speed internet services in Pakistan. They provide internet services to residential as well as corporate customers, and their services include fiber-optic broadband.

It's essential to check the latest reviews, customer feedback, and service availability in your specific area to make an informed decision. You can also inquire about the latest offerings and packages from these providers. Additionally, new providers may have emerged since my last update, so consider exploring local options and customer reviews for the most up-to-date information.