One of my friends studied CSE at Punjabi University. I can share some details about why Punjabi University will be a good choice.

• The most important highlight is its faculty. There are around 72 teachers. Most of them hold Ph.D degrees. 
• It has the biggest library, with a huge collection of books. 
• AC reading rooms are provided for the students and it is accessible 24 hours a day.
• The college faces no disturbances and enjoys a peaceful environment.
• The infrastructure and facilities provided are top-notch. You will get AC labs, well equipped with modern and updated machinery.
• Even the hostels are well maintained as claimed by the students themselves.

All the 3 universities are government-owned, thus have a good reputation. Punjab university is the oldest among the three. It has a very large campus. Punjabi University and Guru Nanak University, on the other hand, were established later on.