Depends on your definition of winning, really.

If all you want is to hear the other person say, "yeah, fair enough, you win", then either
(a)Your opponent is spineless and is letting you win, or
(b)You weren't having an argument, you were clearing up a factual error

The fact is that the majority of never arguments are never truly won or lost, because most of them never really end. People get tired, bored or it descends into a fistfight. Really "winning" an argument involves having a couple of things happen:

  • Getting your point across

    The hardest thing to do in an argument (which is what turns a conversation into an argument). Getting somebody to genuinely see your point, even if they disagree wholeheartedly, is probably the greatest victory you can score in an argument.

  • Exploring your own ideas

    It's perfectly possible to end up vigorously defending a point of view, only to suddenly realise that actually you'd never really thought about it before. This is often the whole point of arguing something. It's kind of like natural selection for ideas - the bad ones get crushed pretty quickly, while the good ones grow stronger and stronger every time you're forced to defend them.

  • Learning

    Unless your name is actually Jesus H. Christ, chances are that you don't know everything. A good argument should at some stage involve uttering the words "Well, I've never really thought about that before...". Regardless of the subject matter, both parties should have gained knowledge by the end.

It's much easier to lose an argument than to win one. Trust me, I know, I lose arguments on a very regular basis. If any of these things happen, then you're not doing much more than exercising your vocal chords. Give up and watch TV or something.

  • Not listening

    The failing of 99.9% of arguments (it's ususally caused bny allowing me to participate). The line between debate and lecturing is a fine one, and many people see other people's opinions as rude interruptions. In the heat of the moment, it's really easy to ignore the other person. Try not to, or you've genuinely lost.

  • Pretending to listen

    Same as the first problem, but in disguise. This is where you occasionally stop and let the other person talk for a while, occasionally nodding to imply that you're listening. But of course what you're thinking is "I will cut in in 10...9...8".

  • Forgetting the question

    It's really hard to complete an argument about early Egyptian agricultural if it morphs into a debate about whether N'Sync could beat up Backstreet Boys. Pick a topic stick to it. If somebody strays off it, bitchslap them, even if that person is you. Especially if that person is you.

  • Non sequiturs

    Consider the relevance of what you're about to say. Consider the context that it's going to be taken in. Your story about Aunt Mable's holiday in Greece may be relevant in a conversation about the sexuality of older women, but not in an argument about breakfast cereal.

  • Don't get personal

    Trust me on this one. It's never worth it no matter how good you feel your point is.

While this is geared more towards factual debates, most of it still holds true for your average boyfriend/girlfriend who-left-the-lid-off-the-marmalade stuff. Or perhaps I'm completely wrong.

I'm not going to argue with you about it.

Of course, if you just want to end the argument, simply yell "NAZIS". Any argument is over as soon as someone uses the word Nazi.