Peach trees, plum trees, and almond trees are at the top of my list. I'd want to be able to make almond milk.
Tartosa would have been the perfect opportunity to add olive trees, figs, and/or orange trees, but I don't know if there will be another good opportunity.
Corn, for sure. Wheat and sugar cane would be alright, too.
I would like to see canning recipes added for more of the fruits we have in game already, including elderberries, as well as any new ones that might be added.
If we get nectarmaking (and we had better get nectarmaking eventually), I'd like to see more varieties of vines, like we had in TS3, not just "grapes."
More herbs: cilantro and rosemary would be a good start.