1. The First 100 Japanese Kanji: A great first step into the world of kanji. Basic, but at first you just need something to help you dip your feet in the water.
2. Berlitz Essential Japanese: Better than I expected, by why bother with non-academic textbook if you're a serious learner?
3. Genki I: This was my real first foray into Japanese. Great series, especially for self-study. Holds your hand but covers a lot of territory. It helps to read it, then go back and read it again. I used the workbook on a few occasions, but not much. NOTE: The link is to the old version.
4. Genki II: The follow-up to Genki I. Goes into more complicated grammar. Again, a great book. I used JGram and Tae Kim's a lot to reinforce my learning with the Genki series. NOTE: The link is to the old version.
5. N3 Speed Master Series: I really liked these, however I didn't use them for long before moving on to N2 materials. It wasn't well edited, though, and some placeholder text was repeated a lot in the grammar book.
6. 合格できるN3: This is just practice problems. Really useful for the N3, though.
7. 絵で見てわかる 日本語表現文型 初中級: This was recommended by a friend. I love it because it was my transition into using primarily Japanese to study. It's a list of grammar points from high N4 to low N2 level, with related phrases lumped together. There are example dialogues and pictures along with a few sparse English notes. It's not perfect, though (some sentences don't give you a very good understanding of the grammar points).
9. Shadowing: Let's Speak Japanese: Okay, so I only ever used the CD (not the book). Still it's great. I realized my listening was weak and conversation skills were even weaker so I found this. Starts slow, builds up. Funny and interesting. Transcribing the sentences helped my ear a lot.
10. 新完全マスターN2 Series: These are amazing for intermediate Japanese and preparing for the N2. The Kanji and vocab books are probably the weakest and least necessary. The others are essential for N2 study.
I know there's been a few others but I can't think of them right now.
Popular alternatives to
The First 100 Japanese Kanj...
AP Psychology Premium: With 6 Practice Tests (Barron's Test Prep)