Tell me about singers in European Portuguese and Brazilian Portuguese.
Well, as a native Brazilian I can give you tons of recommendations
But I'll name only my favorites: Marisa Monte (I dare say she's the widest known Brazilian voice), Vanessa da Mata, Ana Carolina, Zélia Duncan, Isabella Taviani, Cássia Eller, Nando Reis (you could also check his songs with the band Titãs - but notice that some of his songs are very confusing and hard to understand), Arnaldo Antunes (same), Cazuza (I dare say he is the greatest Brazilian artist so far, his life and works inspire many people to this day - and he's been dead for almost 30 years) and Zeca Baleiro.
There are a couple of alternative singers I know and that I like very much: João Guarizo, Toni Ferreira (listen to his 'Saber de uma Alma' ) and Daniel Chaudon.
I like the bands Skank and Kid Abelha, which are more pop-rock oriented.
For EU-PT you can check the artists from that country here > http://lyricstranslate.com/en/country/portugal . I unfortunately don't know any of them...
For singers from Portugal, you could take a look at the country in Eurovision. They have never sung in anything but Portugese (apart from a few half-English songs) in its 48 years of participation. I would definitely listen to Vania Fernandes, she is an amazing singer.
I love this singer, she is from Brazil but this is the only song she performs in Portuguese, she mostly does English
My favorite artists from Brazil are Lu e Robertinho. I've put some of their lyrics on here. They do covers of popular English hits, but half of the lyrics are in Portuguese also.
Also, going off of the Eurovision comment, I like Filipa Sousa and David Carreira (spelling?)