As a child I felt sorry for some of my friends who seemed to me to have a more unloving, 'harder' relationship with their parents. I'd listen to the way they talked to each other, parents putting thier children down, not really interested in their lives, too busy to listen to them properly, and feel so glad my parents weren't like that. Of course this was through the eyes of a child and may have been far from the truth. But I certainly had my opinions and did not feel deprived because my parents didn't actually say they loved me - though we had lots of loving sayings. Had I not felt my parents loved me, perhaps I would have set more value on saying these three words to my sons.
Don't get me wrong, I do feel it's important to say 'I love you' to my sons and I love to cuddle them. I say 'I love you' at least once a day and praise them in all sorts of way in between. I think meanbean has a good point about English people not being demonstrative enough,
and agree that the sort of parents who say 'I love you' are generally (big generalisation) going to be loving parents.
But I also think children can spot insincerity a mile off, even if they do not understand exactly what they are spotting. That's why I think it's even more important that children feel they are loved. And that extends to choosing your moment to say those words. No good saying I'm too busy to play with you right now, but you know I love you to bits. I think it's a bad idea to confuse children like this.
I think my children would rather have specific praise that shows I have noticed them eg 'you were so kind and thoughful to mend your brother's car and it was really clever of you to work out how to put the wheels back on the axel' rather than lots of 'I love yous'. I'm not saying anyone here does this btw! Interestingly, my oldest son, who has had about 20 different teachers so far, really likes the nice but strict ones, the ones who never let anything slip past them, the ones who are always interested.
I could be wrong but I feel my sons will remember the actions that show I love them far better than the endless repetitions of the words themselves. Even now they place more value on the actions, not the words. They never ever ask me to tell them 'I love you'. They will instead endlessly ask me to watch them do this, look at that, sit with them, see their drawings, read to them, stop what I am doing, concentrate on them.
I hope they grow up to know what love really is, to not be the sort of men who say 'I love you' without meaning it.