1. Seinfeld (1989-1998)
2. Scrubs (2001-2010)
3. Frasier (1993-2004)
4. 30 Rock (2006-2013)
5. Parks & Recreation (2009-2015)
I honestly haven't seen that many sitcoms tbh. I watched Seinfeld a fair bit while it was on reruns and the like and dug the characters and their quirky day to day lives...