Maybe a gift basket with their favourite things! I think it shows you care and it offers some flexibility (like, you can adjust the items you choose to put in according to your budget).
If you're the crafty/creative type (or broke like me), something homemade or DIY based on their interests could also work. One of my favourite types of gifts to give (and receive) are just sincere, heartfelt notes. I think those who genuinely like you for you and are close to you would really appreciate anything you gift them, whether it's something extravagant like jewellery, or something more personal like a card with a message (sorry for the tangent! Gift giving is something I just love doing)!