Sorry to hear about your laptop, as you correctly said you were and most other people are often members of the “it won’t happen to me club” that is until it does happen to them. I was lucky, I saw it happen to friends before I became a victim, so I looked around for a solution also. The N-Case is ok if you want to look like a spy, but I wanted something more normal.

I found the pacsafe.com range of anti-theft laptop bags to be perfect for my needs, in fact I have a couple of different ones for different purposes now.
Their MetroSafe 300 fits my little Sony Viao perfectly, but wont take anything larger, so I use their commutasafe when I’m carrying my Dell.