Can't think of much that really hit the spot at 5 months, except books with rhythmical rhyming text - that was the peak time for Hairy McClary - and a cheapo set of plastic keys to chew went down well too.
Later on, the Brio train set and Duplo have been top performers aged approx 1 yr to now (almost 4). Jigsaws only really started around 2 for ds but have been amazing long-term results ever since. Art stuff - he wasn't interested even slightly until 18 months, but some children apparently are. it is great to have really nice art things, like decent multicoloured paper, good quality crayons etc. AVOID CHALKS they get everywhere until children are MUCH older, if you are given some, smile prettily and hide them/rewrap for some other child.
Playdough and all the kit is fun for parents, anyway, but not yet for your dd - next year wd be ideal. I make my own as I can't stand the smell of the real stuff, but the cutters/pressers etc are a laugh.
Don't knock the plastic tat - one of the most successful presents ds had between approx 6 months and 3 years was a horrible plastic 'book' shaped like a piano with 'pages' that played different versions of Old MacDonald, all vile. He loved it with a passion and would keep himself occupied with it for ages.
Really good song CDs or tapes (the latter tend to be shorter which is good, believe me). Tapes of sea shanties and folk songs are much, much nicer than cheapo recordings of The Wheels On The Bus but tbh in my view you need both.