One can assume (like I do) that she didn't want Angel and Spike to fight over her in the very few days prior the big fight. Even in the eyes of a Bangeler it's clear that it would be more than odd, if she sent Spike away, because Angel was back, willing to stay & she loved him more, yada yada. Whether or not, it wasn't about whom she loved and to what extent - she had the mission to win this fight. Period. She couldn't risk any distractions. Besides, she knew that unlike Angel, Spike had nowhere to go, plus Angel indeed had the sources for the second front if one was needed. Also Spike was more useful by her side than anywhere else. So it was natural to send Angel away.
She said clearly to Angel that she needs a second front (which is true) and that's why she can't risk him (honestly, if she was really caring about him, she would have taken the time to make a call or taking news), but Spike is the biggest reason of this. Buffy doesn't even had to talk about him, Angel directly guessed it (and in a romantic sense moreover).
I agree that she doesn't wanted Spike and Angel on the same house, but she clearly put herself at Spike's side during her conversation with Angel ("he is in my heart", "he's different", "is that your business ?"). If she was in love with Angel, she wouldn't be that much expressive on her feelings for a guy she knows he can't stand... Like she had done with Spike later : "It was a hello", "There were no tongues", "I was surprised" (in the shooting script, there is this sentence too). She tries to minimize the meaning of her kiss with Angel, she needs justify herself. It seems natural. This ? It's a thing you do with the person you love...
"I loved him more than I will ever love anything in this life."
You know what ? I like this sentence. Because she comforts me on my opinions about B/A and Buffy's love life.
Like I was saying, she will never love again like she loved during her young years. It plays on a level of intensity, because, let's face it, she was in a period of her life where it was appropriate. But I think it has nothing to do really with Angel. Because now, at this period of her life, if she could love Angel again, or Spike, or Riley, or Parker, or Andrew or anyone else, she will never be that much demonstrative again. It has nothing to do with an "amount" of love for ONE person. It has to do with who she is.
And, 2) it goes in the direction of the idealization she had of her relationship with Angel. She doesn't know him for years, she sees him one time by year (which maintains the fantasy), and she put on a pedestal this period of her love life. It's normal, it happens to a lot of girls, but she'll never find this way of feeling again. She doesn't see Angel like he is, she has an image of him in her mind. That's not my idea of real love.
So when she said "I loved him more than I will ever love anything in this life", it totally goes in the direction of the idealization. She speaks about a way of loving, when she was younger, even if she doesn't realize it. Because she still has a lot to learn by herself (she's still blind at some levels). She's not a liar, but it's the perfect proof of how she put on a pedestal this kind of love. It plays on an emotionnal appreciation, period. But it remains ways of loving.
It really doesn't fit with my definition of love. We all expect to be accepted and loved for who we are. Not for an image of who we are... It's really easy to promise an eternal love to a person you see one time by year. It's less easy to open yourself completely to someone you know and you see every day by your side, because you expose your weaknesses and you have to trust the person in front of you. So, when the "I love you" comes, it's just more powerful and meaningful to me... The strengh of the symbolism is completely different.
Concerning the 'argument' "she lied to Spike when he was dying", oh, please, seriously... I said all what I have to say about why I think she was in love with him. But I think it's a big insult to Buffy's character, and to the importance of the Spuffy relationship in Buffy's heart.
when I look at Season 8 (though I don't care much about it, but it seems to be quite canon, lol) there's indeed not much left of Spuffy. It was clearly implied she knew he was 'undead' again and didn't care enough to go see him.
Okay, I have to say it, her attitude in the comics toward him is the best proof of love that she could give, I just totally love it ♥ Why ? Because, obviously, he's important to her and she loves him. That's why she's so hurt and angry because of him when she discovered he's alive (we have seen her reaction to him in #36 but I guess we'll see later her reaction on the moment). If she was really indifferent, she would react normally... I mean, he doesn't even tell her he was back. How is she supposed to feel ? The last time she saw him, she opened her heart to him. And now, he's back for months, and he doesn't even tell her ? Knowing Buffy, she felt rejected again.
TimeTravellingBunny explains it in a better English than me, I recommend it, really :
http://boot-the-grime.livejournal.com/1380.html#cutid1
It's not indifference. It's the exact opposite.