"Like I said..." has to be the single piece of dialogue I most loathe.
It turns up a lot these days on TV and Radio drama and I've taken vehemently against it.
Perhaps it's my problem, not the line's, but here anyway are my top reasons for hating it-
1. It often doesn't fit the character who's supposed to be saying it.
For example, almost any character who's over 40, or who we're expected to believe is 'posh' (ie. a baddie), is more likely to go with "As I said," (or possibly "as I say") instead.
It's, to my ears, quite a young character's line, and not one I usually expect to hear authority figures use.
2. It's so self-conscious, a character referring to themselves and their actions as though standing back, summing themselves up.
Sometimes that's fine. Mainly, it isn't.
Most characters are driven by forces they don't understand, and as soon as they start talking like this they're on a journey towards either being the kind of complex, realistic, slightly dull people who never get anything done, or unutterably smug and self-regarding cartoon characters- the kind of people who know they're a major character and are acting up.
3. It quite often precedes those horrible bits when you see the writer peeking through and you'd rather not.
"Like I said, that apparently throwaway line before is actually so thematically important I'm going to repeat it now, revealing its significance." I hear gears grind and don't like it.
4. You can normally cut it and lose nothing (bar my annoyance).
5. I'm irrational and ridiculous, but, like I said, "perhaps it's my problem, not the line's."