I hate you all!!!
The most effective way of grabbing a reader's interest is with a heading which is either completely relevant to their needs or is so obtuse it sparks curiosity.
I wouldn't recommend using the same one I have, but it does its job, and a headline only has one job:
to get the reader to read the next line.
Example: a potential client is looking to buy a specific pipe. He's a pipe smoker. You have followed the lessons here at WA and realised that the keyword "pipe" is inadequate. You'll attract people looking for copper pipes, UPVC pipes, drainage pipes etc. You need to move further along the buying cycle and grab the reader who's looking for something specific. Now it's likely that the potential buyer is looking for two things: the pipe he's already decided upon, and the best price. So the headline "Best Priced Peterson Killarney" would seem to fit the bill.
You need to be careful with word order for maximum effect; the line "Peterson Pipes at Best Prices" is likely to be fractionally less effective for two reasons - it's not specific enough (he wants a Killarney) and the first thing that hits him ISN'T the price info. The first heading I typed is better because The user knows when he clicks the link to your page that he's going to find a Killarney pipe anyway. Hitting him with "Best Priced" has the psychological effect of reassuring him immediately. So the headline is relevant and effective.
Sometimes though, you're not selling anything specific but you are looking to get your page read. In that case a bland headline will lose you friends. So here's an example of a headline which will grab interest if you're writing an article on your site about the key steps in searching for a life partner:
"Why I married My Mother"
Weird, but sometimes effective. Always try to think outside the box where there isn't an obvious sale involved. Obviously (I hope) the content will be about traits and similarities which your future spouse might have with the person who brought you up. This sort of thing might lead to an e-book on the hazards of dating; clubs; pubs; where not to meet decent girls/boys; shared interests etc.
Stupid example, I know, but maybe you see my point.