Ok this is shallow.

What I think most of us find is that we have a core set of dealbreakers we're not going to discard, and a set of preferences we think of as dealbreakers but are not. Witness the number of people who've thrown out of some of their "dealbreakers" along the way.

For me (and this is a purely hypothetical exercise, especially if my wife reads this), the core is probably:

-Manipulative behaviour. I'm not gonna stand for it. That's assuming I figure it out, of course. I should probably lump abusive behaviour in here, too.

-Substance abuse. My dad drunk himself to death and my brother's got some serious problems of his own. I love beer, personally, but I don't like to have more than one or two at a time.

-Non-readers. It looks like I don't have to explain this one.

-Incompatible sense of humor. Any partner of mine has think I'm funny at least some of the time, or she'll kill me.

-Evangelical anything. I mean that in the generic sense (i.e., "marked by ardent or zealous enthusiasm for a cause"). Overenthusiastic atheists bug the hell out of me, and I'm not a believer. But I do respect my friends who do believe. At least if they don't try to convert me. There's a threshold here, obviously, that might vary a bit. But I'm not going to church on a regular basis, trust me.

-Authoritarian leader or follower. I'm neither, and I really don't want anything to do with either.

Other than those, I'm willing to negotiate. Like Ayn Rand? Hate cats, SF or punk rock? Own a ferret? Maybe we can work something out. My wife has to chaperone on all dates, however.

Wow, I didn't realize

I agree, my tastes have been expanded by being exposed to my wife's preferences. My reading list is waaay more varied than it was when I was single, as is my film intake. And I daresay her playlist has been expanded both by music I've introduced and acts we've discovered together.

That being the case, I don't know if well-read, etc. is as important as being willing to try new things. Doesn't mean you'll both like those things, but the ability to give them a fair shot does say something about a person.

Oh, and for everyone seeking a partner with perfectly aligned tastes so your house is free of artistic dissonance: Add a kid, and it's all out the window. Mine has definite opinions on many of my favorite artists, and not all of them are favorable. Now he's decided he doesn't like my old Muppet Show DVDs anymore. Not even the one with Peter Sellers. The boy ain't right.