What's the best thing to spend on your children?
Spending time with them is the best thing you can do with them
Spend your love on them, man.
depends on you mean. if your meaning spend as i money... i don't know but if your meaning time then spend like 30 at minimum with your kids if you can't do that even you really need to change how your work or whatever is laid out.
Time and teaching them new things
Love time fun.