I think it’s safe to say that alarms get on most people’s nerves, especially when it’s early in the morning. But that’s the point of the alarm, isn’t it? To annoy people so much so that they feel compelled to wake up, just so they can shut the alarm up. By then, most alarms will have achieved their goal, which was to wake the person up in the first place.
One such app is Wake. It doesn’t have the most annoying of alarms, but it’s enough to wake you up because of how you’re supposed to snooze the alarm.