Pulled this out of the collection today - as much as the debut could also be considered a classic this is the one where they added the additional polish and released a great set of tracks from start to finish. This is arguably one of the album releases that sent 80s hair-metal to the grave.

From Audiooxide

Doolittle balances boisterous oddness with sweet and sugary pop tunes, making it not only their most intriguing record, but also the most accessible. It breathes beauty, mystery, and humour, and nothing else sounds quite like it. Inside each song lies at least one great moment, whether it’s an infectious guitar riff, a killer vocal hook, a captivating instrumental breakdown, or Black Francis concluding that, on the basis of people being 5 and the Devil being 6, God must be 7. The surrealistic nature of Francis’ lyrics is a vital part of that distinct Pixies sound, and it continues to be absurdly enjoyable: if he’s not contemplating biblical mythology, he’s singing about the whores in his head, or barking like a dog.