Not 100% of the time, but I have been able to boycott a few things in life that I would otherwise genuinely like.
I'm on for boycotting Activision-Blizzard — I do like stuff from the publisher and was even looking forward to Modern Warfare this month but I also don't value the content I consume from them enough to feel like I'm missing out on much by dropping them, so it will be pretty easy to avoid going forward, and I'm also not feeling terrible about purging the existing content from my collection where I can, though I'm not convinced that doing so will actually achieve anything — they already got my money for that stuff.
I've been able to give up Chik-Fil-A for a couple of years now. I personally like the taste of their food and it's been hard to resist at times, but I've pulled it off and intend to stay the course.
but, on the other hand, giving up Apple isn't possible in my mind at this time, even though I strongly disagree with their actions in response to CCP pressure. The reasons why have a lot more to them than I have time to fully explore right now, but even if you hate Apple, I'll give the benefit of the doubt that you're able to reason out a few good reasons why it's not so easy to ditch. Also, in the realm of consumer technology in particular, I think every major player has dealings just as severe as Apple, they're just not having to about-face on their public-facing image and stated ideology about it like Apple is.
Entertainment and fast food? Easy. The tech that helps drive my daily existence? Mmm, not so easy.