Windows to Linux

I'm thinking about switching to Linux. Specifically Ubuntu or Fedora. Anyone want to tell me why or why I shouldn't? Currently using Vista Home and I like it but I just want to see what else is out there. Plus if its more secure, thats always a plus.

I once installed Ubuntu, ran the updater and it trashed my system.
Quite handy, it made me realize that Linux is worse than Win95 in less than 15 minutes after installing it.