Only Fools and Horses at 40

[Brekkie]

I think the last comedy hit that ITV had was Duty Free.

Depends how you term a 'comedy hit' but what about Mr Bean, The New Statesman, The Upper Hand, After Henry, Benidorm? Not sure if Men Behaving Badly counts

There are other examples, Thames had quite a few fairly long running sitcoms in the late 80s as well as After Henry. There were quite a few weekend sitcoms that did fairly well like Surgical Spirit, Second Thoughts

And later than that you had Barbara and Hardware - granted not the breakout laugh out loud hits the BBC were seeing but both had multiple series .

ITV2 has had some success too, most noteably with Plebs.