If you go for knitwear, make it for 6 or 18 month age range because it won't get worn in the summer (unless they're in north east Scotland!). A melange colour scheme will work for any child (see DS modelling one his great-aunt knitted for him when he was small), as will green or red.
A really nice blanket in very soft yarn would be lovely - what DS called later his bears' blanket, ie, the one his soft toys were snuggled up in at bedtime!