I still get a little excited talking about the early Jack Taylor books — there’s something raw and smoky about those first entries. If you want the original publication order (the way I read them when I first tracked down copies), it goes like this:
'The Guards'
'The Killing of the Tinkers'
'The Magdalen Martyrs'
'The Dramatist'
After those four the series keeps rolling with titles you’ll bump into later: 'Priest', 'The Devil', 'Purgatory' and then 'Headstone'. I tend to read in that order because the character development and Jack’s personal downward drift feel most natural that way.
If you’re new to the series, start with 'The Guards' and let the rest follow — the tone and Dublin underworld feel build on each book, and reading in original order keeps the small character revelations satisfying.