S.L.
Our extended family tends to go a little overboard with Christmas gifts, so my son doesn't get a ton from us. Last year (he was 20 months) the big thing we got him was an easel from Ikea that was like $30. I got him a smock, chalk and finger paints and he was a happy kid. I think we also got him a puzzle and a set of wooden cutting food. However, he got a tool bench from my parents and a bike from my in laws, plus tons of books and puzzles and blocks and clothes and other things. The thing with kids at that age is that they are so excited about the first thing they open that you need to convince them to stop playing with that to open the next gift. I think 3 is probably enough as long as you are sure he'll love them all, but I think 4 or 5 is totally reasonable too.