I'd personally love a harpist stamp.
I'm kind of sad I can't show off my instrument. I'd also love a nicer 'joined in 2016' stamp. There is nothing wrong with the one that we have, I just don't care for Monkeys. Maybe featuring the oil lamp Hanukkah dog? Or the PPS Cheetah?
No, wait... The Cinnamonroll! I'm sure everyone would love that one. <3
Also maybe an 'I love to read classics' addition to the I love to read stamps? I for one don't really have a genre preference but I have a soft spot for classics regardless of genre... Les Misérables, Pride & Prejudice, the War of the Worlds. <3