Alan Carr's book works very well for some people, bit of a personality thing.
Nicotine replacement makes it twice as likely that you manage to stop than any other non medical method and Zyban is twice as likely to be successful than the nicotine replacement.
There is no evidence to support any of the nictonine replacement therapies over one another (they are all as effective so choose what you fancy best).
There are some undesireable sideeffects possible with Zyban and some categories of people are not suitable for the medication (or vice versa depends on your viewpoint)
Those that have tried to give up a few times are most likely to succeed.
Don't give up, giving up!
Best of luck
FD