Hello Eladio-- what a nice surprise! Hace mucho tiempo...(since I studied Spanish).
Actually, I don't think we say What a good advice!. We say What good advice! or What a good piece of advice! Advice is uncountable except in the very specialized case of a commercial document (e.g. a shipping advice).
Thank you Marius, but I do not understand very well. Does it means that I can say:
What good adive! and What a good advice you have given me! ??
We say: What a lovely day!; What a pretty woman!; What a beautiful forum is this! and these sentences are all correct (I believe). Would you be more explicit, please!
After reading Marius's post, I checked again. It is still not generally countable, but there is another case where a plural form is used:"information or notice given -- usually used in plural."