I just used an OnGaurd lock. Nothing special, no frills. Then again, mine is in a bit safer location.
Best bet is to use a chain or cable to lock the bike to an object... light pole, tree, etc. Even with a disc lock, they can pick the bike up, or even put a dolly under the tire.
I've read all sorts of reviews on the alarm locks... they ranged from awesome to PITA all for the same lock. Basically, when they work right, awesome... when they don't, you have a screaming banshee in your ear and outside your neigbor's window at 5am, of which you can't shut up because of some random issue with key/lock.