I voted "I don't" but that isn't completely true. I will not buy games full price from companies that I have a problem with. I will, however, get their games if there is a huge sale (think steam 75% sale or something). The more I dislike a company the lower the price has to go before I even think about it (assuming a game I want, I can just ignore ones I don't want).
An example of sorts. I really wanted to get the game spore (this is before it was released). I loved most sim games and this was supposed to be huge, but there was this problem of some nasty drm (one of the early online-activation required games). I didn't buy it and found out, through reviews, that the game was actually pretty mediocre. Fast forwards until last month, I had an opportunity to buy it for 3 dollars. I can live with 3 dollars even if the game might refuse to install at some point in the future. I bought it, played it, got bored, and might uninstall it soon. But 3 dollars was a good price point for that game for me.