Well, in the last three days mine's watched way,way,way too much. This, to be fair, is because she's got a streaming cold, and at nine months preg, bus trips out have temporarily ceased in the last week.
Usually we have a house rule that the tv is defn off between the hours of 8ish-3.30, then on for half an hourish, and then off again. But if she's feeling ill, she does want to sit in front of it. I don't fret too much, to be honest, if she's poorly. Oh, and she is an early riser, so does tend to have at least an hour in the morning before the 8ish cut-off. And sometimes I'm tired, so we both cuddle up and watch a bit more than usual.
I worry about it a bit, but when I haven't got my 'guilty mother' hat on, sense says that so long as children are happy and busy and doing other things too, it isn't the end of the world if there are occasional 'tv' days.
Zebra - the one thing I've found with mine that winches her happily away from the box when she's into 'tv watch' mode is to teach her to turn the thing off, praise her to heaven when she does, and to tempt her with loud exclamations from another room about something exciting I'm doing. She goes bonkers if I try to turn the thing off when she wants tv, but doesn't seem to mind turning it off herself. And as for video's.......well, we cracked that one because, err, 'Only Daddy can use the video machine'. I know this does absolutely NOTHING for gender stereotyping (and, for the record, I can use the video machine) but it does mean that she never watches them during the day. I really should think of something else, though, otherwise she'll grow up thinking that Mummy is a complete banana