Luis Cernuda could be one of the best poets with whom you're unacquainted. Born in Seville in 1902, he was one of many 'transgressives' of the Generation of '27 movement forced out of the country due to the Falangist régime; as was the case with many of his comrades, Spain's loss was Mexico's gain.
His evocative combination of insatiable longing and curious imagery lit my imagination more than any poet since the dual whammy of Larkin and Plath. I could not rest until I read his entire oeuvre. This led to the (amusing, in retrospect) sight of me going around the arch-conservative Cantabrian town where I lived, essentially looking for a librería that stocked an unabashed writer of gay poetry. Of course, he was nowhere to be found, though his newly accepted friend, Lorca, winked from the clustered, tobacco shelves.
It is a real shame that no great effort has been put into spreading this great, brave and ambitious man's poetry. I try every year to translate the majesty of 'No es nada, es un suspiro' and always come short. Check it out - and the suitably titled tome, Invocaciones - and you shan't be disappointed, you have my word.