ChristoChang,
I swear by the Brenthaven Pro case. Yes, it's expensive, but it is designed to be the only bag you will need. It provides about the best protection money can buy for your laptop (go to the Brenthaven website and check out the design of the sleeve, etc.), but it goes far beyond that.
The Pro bags have pockets for just about any computing accessory you can think of, plus an "attache" pocket that serves very well as a "mobile office." I manage to fit my entire life into the bag, I carry it with me everywhere I go, and I feel safe tossing it around casually; no "babying" necessary.
Scott
p.s. The 17" bag does, in fact, fit the 17" Macbook Pro