Best book to learn/improve at Java

Hello all,

What is the best book to learn or improve at Java in your opinion and why?

Thanks.
-MEl

It really depends on your current level. If you are a beginner, I've heard Effective Java or Head First Java recommended (but I haven't read them myself). If you're a bit more experienced, Java Puzzlers is a great way to dive into the more advanced stuff (I'm reading it right now, it's great). And if you want to take Swing to the net level, Filthy Rich Clients is pretty awesome (I read that a couple years ago, good stuff).

But really, your first and best resource should be the tutorials and the API.