There isn't a single or simple answer to
this question. The right type of mortgage
for you depends on many different factors:
Your current financial picture. How you expect
your finances to change. How long you intend
to keep your house. How comfortable you are
with your mortgage payment changing.
The best way to find the "right"
answer is to discuss your finances, and your
financial prospects, and your preferences
frankly with a mortgage professional.