Seinfeld- Jerry and Elaine are exes and breify get back together at the end of season one
Friends- lots of romantic entaglements but mainly Chandler/Monica, Ross/Rachel, and Joey/Rachel
How I Met Your Mother - two of the main characters are a steady couple, the other three are a love triangle
Big Bang Theory- by the end, it’s three couples and one single guy
Any shows like these where the main characters never date each other or hook up with each other?
That is a tough call. She was a series regular, therefore a main character, but not really part of the core group