We're looking to get some Lego as a birthday present for the son of friends of ours. He's going to be turning 4 in a couple of weeks, is just getting into playing with Lego (& plays with mine when he comes round to play with my daughter) but doesn't have any yet of his own.
Having a look as currently obtainable sets that I think would interest him, I think I've narrowed it down to being between #60088
(I picked one up when I saw it stupidly cheap a short while ago.)
Playability is probably the priority here so I'm leaning towards the Starter set as there's more things happening in it but I'm open to other thoughts & opinions on the two sets (& even to other suggestions)