A pretty great gay free verse poet and beatnik. His most famed work is Howl, a three part poem (with a poetic footnote) that was Ginsberg's response to the social climate in America, in addition to parts of his life. Became very involved in spirituality, becoming a Buddhist in the 1960s. He wrote tons of poems, which I definitely recommend you read. Though later on his stuff got weirder.
Allen Ginsberg was an excellent poet, but in his later years he wrote some pretty weird poems, like, "Sphincter" (which, albeit it being strange is funny).