Aren't there times when you long for a screwcap bottle of wine? You've put the corkscrew in, pulled, and only half of the cork has come out, or the corkscrew has come out without the cork, except for a spray of bits of cork â€“ you know you're going to be drinking cork with your wine.
There are two problems here â€“ most commonly the corkscrew, more occasionally the person trying to open the bottle.
Trouble most often occurs when the spiral of the corkscrew doesn't insert itself into the whole length of the cork, so that when you come to pull on it you don't pull all the cork out, leaving the end still stuck in the bottle. If you then try to screw the corkscrew into the remaining plug, it almost always gets pushed back into the wine where it floats about and irritates you. This happens frequently with the worst possible type of corkscrew, widely distributed (usually heavily chromed) and giving the appearance of being a good quality piece of kit: it has two arms that gradually raise themselves as you screw the spiral into the cork; you push down on the arms to lever the cork out. These corkscrews are an abomination and should be banned.
Avoid also corkscrews that only have a short length of spiral, because you have the same problem as above, namely that you end up only pulling half of the cork out. And avoid those that look like an Archimedes screw, where the spiral is made by means of a lathe cutting into a solid block of metal (similar in form to a carpenter's screw).
The "Waiter's Friend", a corkscrew which has a lever device (so when you fold it out it makes an L shape), is fairly effective, provided that the spiral itself is sufficiently long. You need to be careful, though, that you lever judiciously, because it is possible to chip the top of the bottle â€“ a little bit dangerous!
For younger bottles of wine problems arise less frequently. It is with older bottles that you need to take more care â€“ particularly important because older bottles tend to be better bottles, so you don't want to make a mistake. I am not convinced by the Screwpull (though I use one all the time for younger bottles at tastings because it is quick and efficient). Here is my advice: choose a simple unmechanical T-shaped corkscrew (with a handle you can get a good grip on, that does not cut into your hand when you pull on it) where the screw is a steel helix of sufficient length â€“ at least 2 inches long â€“ with a good open pitch so that it gets good purchase on the cork; and then just pull!