The best relationships in my life are those founded upon the principle of debate.
Debate is an art very different from that of argument, which is more closely tied to the idea of fighting, of two opposing sides. Debates are conducted by two intelligent people -- intelligent about the value of relationships, that is -- who are able to open up to each other and not necessarily agree upon things, but can politely and genuinely agree to disagree.
Fights/arguments are conducted by two (not necessarily UNintelligent) people who have probably lost touch of what they are discussing and where they are hoping for the discussion to lead, and hence, it becomes a fight.
We're all different, and that's something we'll eventually have to acknowledge in every relationship. No matter how close you may be with someone else, you have disagreements in small, petty matters and in larger matters such as lifestyle habits and whatnot. Often times, I witness these disagreements turn into dysfunctional relationships that simply cannot stand because one or both of the individuals can't reach a mutual consensus. Why? Because they're fighting, and when you fight, the tendency becomes to (1) tune the other out, (2) ramble on and on about your point, (3) lose much of your own sensibility.
Debates work a bit better in that you realize there's a disagreement, each person expresses him/herself fully without interruption, then you look for some common ground or simply try to understand the alternative perspective. It sounds a lot like a formal set up for discussions, but it's really not. It may be methodical in a sense, but it really does work. It's not frustration-proof, but then again, no disagreements are.
Hold onto your relationships, and don't let unnecessary arguments create dents all over them. Debate a little more, and you might just notice bonds growing stronger as a result of disagreement. It's a beautiful thing.