Yunzi wrote:- a newbie (30- 15 kyu).
The Second Book of Go
1001 L&D problems
Opening Theory Made Easy
Tesuji (to just read over, problems are quite better at the next step, but of course, try)
Lessons in the fundamentals of go
Edit: these, except Second Book of Go and LITFG are probably more suited for the next step. They are more of a bridge: start them all as early as possible and keep working on them as you improve. After all, 30k-15k is usually a pretty fast spot, if you start with good reading material you'll kick-start better.
Yunzi wrote:- an amateur (14- 5 kyu).
Attack and Defense
Fighting Fundamentals
Lee Chang'Ho Tesuji 4 & 1
Lee Chang'Ho Tsumego 1
Yunzi wrote:- a good player ( 4 kyu and more) ?
Whoah, "good player." I just had a (KGS-induced) ego bump

Segoe-Seigen tesuji (3 volumes... Let's assume it's just one volume ok?)
Lee Chang'Ho, the remaining volumes (again, assume it's just 1)
The Direction of Play
The Style of Go Seigen (could be read in the previous step, and I wanted to add some game review book)
Fairbairn's edition of Gateway to All Marvels, or the Korean re-edition, whatever you fancy
Edit: I'm probably not a good example of restricting my go book purchases. I have more than 100 books, probably around 120 counting PDFs (legal ones, Jonathan Hop sells SYWTPG as a PDF bundle) and SmartGo books.