I use the KRYPTONITE disk lock. In addition, I always put the "stretchy" thing on the lock and my handle bars (as a reminder) so I don't drive off with the lock on. Could be VERY embarassing!!!
+1, and if you do forget
to take the lock off, you want go very far
. Another safty factor I do is I always roll my bike before I start just incase I ever have a BRAIN Fade and forget to unlock anything
. Falling on your BUTT in public is really embarrassing