I've seen each series in their entirety at Least twice.
3. Brooklyn 99 (a new season is in the works)
2. Malcom in the Middle ( a classic, as a kid I obviously identified with the Malcom and in his siblings as an adult I identify with his parents) ((it was hard for me to accept that Bryan Cranston, aka Hal, a man more or less who I consider one of the goofiest characters ever created and a good father to boot, could turn around years later and play one of those cunning of anti heroes (???) Ever portrayed in media.
My #1 spot goes to Seinfeld
This show is nothing short of incredible. Great characters, absurd situations, extremely quotable. I just finished my re watch of the series. Not sure how many times that makes it but its a must watch.
Please note Malcolm and Brooklyn 99 are the most accessible Seinfeld can be a bit outdated at times.
How I met your mother and Friends are worth mentioning but I am seeing that the general consensus is that it is popular to hate on both shows.