Teach Yourself Irish Book/CD Pack by Diarmuid O Se, Joseph Sheils (Teach Yourself books)
Speaking Irish (DVD Edition) by Siuan Ni Mhaonaigh, Antain Mac Lochlainn (McGraw-Hill)
Colloquial Irish: The Complete Course for Beginners (PB + CD) by Thomas Ihde, Roslyn Blyn-LaDrew, John Gillen, Maire Ni Neachtain (Routledge)
Learning Irish: An Introductory Self-tutor by M O Siadhail (Yale Language)
Progress in Irish: A Graded Course for Beginners and Revision by M. Ni Ghrada (Edco)
Buntus Cainte by Tomas O'Domhnallain (An Gum)
Alternative suggestions, or indeed dis-recommendations, very welcome as well - these just happen to be the best-selling on amazon.co.uk.