And stayed a hit. Are there any official numbers on such things?

For "long running", let's go with meaning on for at least 5 years.

M*A*S*H had five different timeslots in the first five seasons (this is just the fall schedule, might have been more changes midseason). Season six is the first time M*A*S*H kept its fall slot from the previous year. M*A*S*H moved again in season eight, where it remained until the end.

I think All in the Family may lead the league in this category, if not the show will be right there at the wire:

Season 1 Tuesday 9:30-10pm

Season 2-5 Saturday 8:00- 8:30

Season 6 Monday 9:00 - 9:30

Season 7 Wednesday 9:00 - 9:30 &
Saturday 9:00- 9:30

Season 8 Sunday 9:00 - 9:30

Season 9 Sunday 8:00 - 8:30

5 different nights, 7 changes in all.

i heard the Jeffersons changed time slots about 15 times

Two sitcoms I remember got moved around a lot. They were WKRP in Cincinnati and 3rd Rock From the Sun.

I think The Jeffersons has the most as far as long running sitcoms with at least 15 different time slots. The most common time slot was on Sunday night.

WKRP in Cincinnati aired in at least 12 different time slots for 4 seasons. 3rd Rock from the Sun aired in at least 13 different time slots for 6 seasons.

Futurama may not technically be a “hit” but it is well known and has had a good following over many years.

The first five seasons of Futurama on FOX didn’t really get a consistent timeslot and sports events running long would often “bump” the show.

Its been on other networks in different timeslots over the years. It also has had many years in between seasons.

The shows that came to my mind right away are:

Newsradio: aired on NBC for five seasons and was notoriously moved around the schedule at random. It had 11 timeslots over it's five seasons.

3rd Rock From The Sun: This another NBC sitcom that aired in the 90's and moved it's timeslot frequently. NBC never seemed to be sure where to place this show; but it was always moving it.

Coach: I feel like this show had a steady timeslot for some of it's run but towards the end it began to get shifted around a bunch.

NewsRadio was never a hit.