I would not compromise on religion.  Though raised as a Roman Catholic, I became agnostic for several years, and entirely atheist this year.  The Christian idea of a "God" and "heaven" are simply too unbelievable for me to believe.  If in a serious relationship, where the idea of having children was seriously considered, I would not compromise on bringing religion into the family.  It would make me a hypocrite to practice religion since I do not believe in any of it, and I would also be falsely informing my children.  Religion-free, or deal-breaker.

The one thing that I will not compromise on is I will not date a smoker. I won't even entertain the idea of getting involved with someone who is even a social smoker! I am willing to compromise on everything else.

I agree with a lot of what Mary had to say below. In my opinion, opposites only work well for movies. The best relationships are built on some sort of common ground, but that’s not to say that there isn’t a yin & yang effect in those relationships - there’s always a healthy balance in relationships that work. I think it works the best when the individuals share the same values, enjoy the same activities, and something that’s important to me personally, their sense of humor. If you can’t enjoy or tolerate what they find funny or vise versa it’s almost always not going to work. 

I wouldn't really call Megan’s parents opposites just because they differ racially. Most couples work because they highlight traits and qualities that each admire or adore. I’d guess that’s what brought them together.

Bottom lining it, I wouldn’t compromise on religion. I can’t imagine the lifestyle difficulties not being a cause of many baseless arguments and each relationship already comes with enough, why add more?

Wow good timing with this episode. Just last night my boyfriend of 4 years and I decided to break up, and a major reason is because we’re total opposites. We love each other and have fun together, and for a long time it was easy to ignore our personality differences because of this. Not only do we not like the same TV shows and music etc., but I’m definitely the up for anything type of girl that thinks with the right side of her brain and is optimistic, creative and emotional, whereas he is logical, pessimistic, more cynical. We’re also not seeing eye to eye on major life goals like marriage and children (I want to experience that in life down the road, and he doesn’t at all). We’ve pushed aside these underlying issues and tried to look beyond them for a long time, but they eventually surface and we know it’s just for the best to move on. It’s extremely hard to have to be realistic and face the facts that we’re just too different. So I think Meghan’s parents relationship is a special one that has got to be a rare success, and I wish everyone luck who's trying to make an "opposites attract" relationship work, because I've learned my lesson that it can't last forever.

I think this is a really interesting discussion topic.  For me, the core value I will not compromise on is open-mindedness.  I honestly don't care whether my guy stands on politics, religion, money, hobbies, social issues, etc., as long as he is respectful of my views and beliefs and those of the people around him.  Closed-minded extremism is the number one turnoff for me.

I am anything but articulate in this episode.  Let me try to write it out....

I haven't had an extreme "opposites attract" experience like Meghan, but knowing her parents, I know it can make for a beautiful relationship....and hot kids ;)

For me, I enjoy dating men who come from a similar background, speak their mind, and like a good adventure.  Of course it's a bonus if he appreciates food and fashion, but I also love learning new things, so if his hobbies differ from mine, I'm always up to try out something new.

In the long run, I feel like compromises shouldn't feel like your compromising anything, but instead doing something you know the other person will appreciate (and keeps you out of the dog house!).

However! I have to add this!  While dating, don't compromise too much.  If you're overly eager about anything, I find it to be a huge turn-off for men and women.  Be yourself because down the road, you're not going to want to conceal anything and you want to be happy knowing he/she loves you for who you really are.

That's the advice from a single girl.  haha.