Nancy Stenson

Relatively few topics covered, but they are covered in detail; essentially, narrow but deep. I suppose this was done for pedagogical reasons, though it could be for financial ones, too (make sure to buy "Intermediate Irish" next!). The exercises were very useful.

I don't know if I'd say this book contains all the grammatical concepts of "basic" Irish, but it's without a doubt very helpful on the road to getting you there.