We've got the Fridge Phonics. In fact, I've got 2 sets as each of my children's names have 2 of at least one letter so we couldn't write out their names with just one set.
DD (1) loves them and already knows how to press the button to make it sing the alphabet song.
DS (3) is not so bothered but does play occasionally and can now pick out letters when asked. Not sure it's helped with his phonics yet but might come into its own a bit more once he's learning them at school.
TBH having them stuck to the fridge in the kitchen means that generally, if we're all around them, I'm trying to cook/wash up/clean kitchen rather than have time for playing. We don't play in the kitchen very often. Bath letters have worked a lot better for that.