Well, ok. I’ll bite. This could be fun. Based on my current (and I hope permenent)SO:
You’re beautiful."
People telling me I’m beuatiful has never done much for me. It’s not like I have all that much to do with it…he thinks I’m beuatiful and that makes me happy. But I don’t have to hear it.(Well, maybe if we’re going out somewhere and I’m feeling insecure).
“You’re a great lover.”
Much more important that being beautiful. But I’d rather he showed it than said it 
“You’re so smart.”
Always good. Better than beautiful. And particualy in his case 'cuz I know he’s smarter than me.
“You’re my best friend.”
Bliss
“You’re the most important thing to me.”
Difficult. I can’t be the most important thing to him right now because he’s got too much else he has to deal with. So him saying that would make me feel I was weighing him down. Though I want to be important to him.
“I would never lie to you.”
Bullshit. Everybody lies. You can’t be in a relationship (one that survives) without a lie her and there. I would never trust someone who said that to me.
“I have never cheated on you.”
Complicated. First of all we have an open relationship. So what “cheating” is may not be what is normally considered so. But more importantly, are we talking about the saying or the doing? I don’t need to hear it. I just need to trust him.
“I’d be lost without you.”
Not good. I want to help him. I don’t want him to be needy. Not good in either direction.
“You’re funny.”
Well, unless he meant my crossed eyes and unusually positioned nose…saying I make him laugh is a very good thing.
“I love you.”
Good. Always good. I guess with the exception that some guys say it because they think they have to. But some don’t. And that’s very very good.
What else? When I got depressed he would hold me and say “I’ve got you”.
What else? I wrote him about going to a book sale and he wrote back something about pictuing me going throught the book and exclaming over my finds and that made him smile. And His writing that made me smile. That;'s what worked for me. So…I’m sorry for you men, once again the key to a woman’s heart is getting to know that particualr woman. Still no Cliff notes available.
What else? Well, there was that noise he’d make when he was about to come. I loved hearing that.