from a purely traditional way Cafe con Leche is good for breakfast,but thats it. Now of course Spain has change too, so Cafe is use anyway you like.
Cafe solo is good after a meal, cortao is good a counter bar, and cafe with liquor is good any time :
I like mine still cafe con leche in the mornings;cafe solo after lunch, and cafe con licor 43(or similar in my area) at late late evening meal.