Originally Posted by
2old
Take a look at the Altor SAF. Can't cut it in a reasonable amount of time and is virtually pick proof. Another good choice is the Hiplock D-1000.
My neurotic take on that lock - once the thief realizes the futility of trying to defeat it, they take the angle grinder to the bike itself! Thief: "If I can't steal it, the owner can't ride it!"