Necessary

You need the article in the second one for formal writing.
The third one is nonsense.

Rgdz, - A.

Oops, I missed the for #2.

Thanks, Avangi!

In respect to #3, how about this?

This book is good to read.

I know this structure looks similar to #3 but slightly different in semantics.

That doesn't sound good to me.

I'd say

This is a good book to read. or

This book makes for a good/fine read.

Liveinjapan This book is good to read.

The structure is quite natural to me. Perhaps it's a regional issue with others.

I remember when I was much younger, someone said, "You're nice to kiss." Why would I remember that? Anyway, it sounded good at the time.

This car is fun to drive!

LiveinjapanIn respect to #3, how about this?

This book is good to read.

I know this structure looks similar to #3 but slightly different in semantics.

The adjective itself (necessary, good, etc.) is what determines whether an infinitive can follow. Some adjectives allow the infinitive; others do not. good does

Thank you all!
It's a great thread!

I think the difference between "This book is good to read" and "This is a good book to read" is that with the first, you're expressing your enjoyment, while with the second, you could be recommending it to someone else.

AvangiI think the difference between "This book is good to read" and "This is a good book to read" is that with the first, you're expressing your enjoyment, while with the second, you could be recommending it to someone else.

That makes sense, A.