The problem with Genki (1+2), is that whenever get the textbook out, or even read the word ‘Genki’, I read it in the voice of the donkey from Shrek saying ‘DONKEY!’, and this kinda makes my studies that little bit less serious. A tough problem!
On a more serious note though, Genki has some useful examples and explains grammar concepts well. Minna no Nihongo is a bit slow, but also excellent. After picking up some basic grammar though, the best way to go is listening and speaking, as your understanding will be bolstered by what you pick up from there.