Wharf is perhaps the card I would put at #1 in the "I can't ignore it" department. It's very good in most any strategies. Rushes are usually the only thing you ignore it for, but oftentimes wharf is strong enough to give an option to beat a rush.
Here is a game where I ignore it full stop - in an engine:
http://dom.retrobox.eu/?/20131006/log.514b5511e4b0b79c883b5e3b.1381080622159.txtNow, I am not saying a free wharf wouldn't help my deck here. But there is enough other important stuff going on that, well, I don't think it's ever the right call for my deck here. Counterfeit to clear me out, ironworks for actions, menagerie for the engine, armory to grab components, bridge for big economy, storeroom to make everything grease together well. I don't think I actually played all that well, but I wanted to share, because this kind of depth makes the game great.