well, when other people get involved, this will lead to jealousy. or indifference, if you think about it.

I voted hate because it's the exact OPPOSITE of love. Therefore, hate is worst for love.

I think the most 'annoying' fact is pride.
seriously, it's hard enough to deal with jealousy, but pride makes you deny everything you feel. either love / hate.

as for boredom, well... actually, if you can feel you're bored with someone, I don't think you truly care / love him/her.
I mean, do you ever feel bored with your family (don't count the 'blood-connection' thingie), or your best-of-the-best friends? well, it never occurs to me. I care and love them so so much, I'll do almost everything for them. I don't want to be separated with them.
BF / GF is not supposed to be different.

you need to realize something first before you make a decision. Love, hate and sorry is strong words. it's different from one person to another. do not use it lightly, for you never know what depth it could be for one person.
you can say lightly 'I hate him', but it could means the end of his world. you'll never know.
now, before you say 'I love you', consider it again and again. you might wreck someone else's life if you're not careful.
it happens to me.

so I cannot count 'hate' for my first choice, because I won't use it, even when I want to end a relationship. it will never because of hate.

I said jealousy, but really lack of communication is the biggest problem. I chose jealousy because I have seen the negative effect it has on both primary parties (i.e., the couple) and secondary ones (i.e., their friends, esp. close ones, i.e. me). But the jealousy stemmed from a lack of genuine communication; there were feuds and tifs and scuffles with no apparent cause that seemed to exist just to exist and never truly got resolved. Communication: it does a couple good.

Voted 'neediness' only because that's a big cause to relationship problems I've noticed, but it's actually not necessarily 'neediness'. It comes wrapped as neediness, where you see one or both parts of the couple being so completely dependent on the other that everything just falls apart - or, even worse, they persist in a relationship that needs to end but are so oblivious to it all they don't. A friend and I were just discussing this and how we're noticing it even at our school (Christian university), and for girls she was tracing it back to fathers who were either absent or just plain crummy and weren't the proper model of Christ in the home - so the girl grows up either acting for attention or hating men, because she wasn't loved like she should have been loved growing up. I can agree with that to an extent: I come from a single-mother home - my dad died when I was young, and my mum never remarried - but I was blessed with an amazing church family who loved on me and showed me God's design for families. My friend was commenting on how most girls in this situation, even from Christian backgrounds, weren't taught to believe that God is sufficient no matter the circumstance. They just see God as another man who's going to walk out on them instead of the Father whose heart is breaking because they were never loved like He wanted them to be.

That's really what I call the biggest problem in relationships. It happens with unbelievers because they just don't know to model their relationship after Christ. It happens with believers because for one reason or another they either don't know the model or are still not trusting God to be all they need. In an ideal relationship, the man and woman are both running hard after God and God works it out that they look up one day and notice the other running beside 'em; it works like a triangle, where as they run after God they end up running closer together. People jump into relationships too soon, too. You need to work on yourself and get your heart right first, learning how to love on people and yourself before you'll ever be ready for a relationship. (Like my friend said: if you don't know how to love on a brother in Christ, how could you ever love on a future spouse?)

There's also the general confusion the culture has towards love and relationships. Globally you'll notice people toting this romantic, all-encompassing love that's supposed to move stars and make you all happy-go-mushy, and this is the love that people have bought into. They believe that's what they're to be looking for, and when they find it they're happy for a time - I think the euphoric period's supposed to last about two years, but I'd have to double-check my sources. Once that happy 'in love' feeling starts to wear, though, reality slaps you in the face and you realize you're actually with this other person who's not perfect and doesn't complete you like you thought. Using the cliches, he leaves his underwear on the floor. He cooks but makes a mess and leaves the dishes for you. He watches too much sports. The list can go on and on here.

Again: it all comes back to people not understanding what relationships are supposed to be. Your mate is supposed to be a helper - a companion - but he's not supposed to take the place of God in your life. If you depend on him to be everything, you lose sight of Who is supposed to be everything. The kind of love you should be chasing after is a love that can move stars, but in truth it's the love that created those stars - and that's not something you're going to find in a human. Once you know about and understand that kind of Love, Love that was deity but humbled Himself to the death of a criminal for people who spat on Him, you'll be able to love on others properly. It's a sacrificial love, and it's not the kind of love the world totes.

. . .so, really, I guess I should change my answer from 'neediness' to 'other', because what it all comes down to is a misunderstanding of what love actually is.

(. . .I love your polls. I get so soapboxy, and I honestly never mean to. xD )

~ Ver

depends to a very large extent on the people involved, and whether the "romantic love" in question is the usual mere neurochemical cascade (half-life of @9 months) or if instead it encompasses true compatibility, affection, mutual respect, etc...

Other -- games and dishonesty. If you are just honest about what is going on with you, what issues you have, etc., etc., things go a lot better.