What is Love?

Love, love--it's everywhere. But what is it--really? I understand there are several forms of love; from friend love to sibling love all the way to God's love. It seems quite unique--but I've been asked the question a number of times, "What is love", or "what does love mean to you"? I get friend love, parental love--even Agape love from God and for God, but my concern is that love that exists between members of the opposite sex, i.e. husband/wife, boyfriend/girlfriend.
While I don't fully understand what that type of love is, I think I've had it twice in my life. Consequently, both times--"love walked away", so to speak. I remember a line from the movie Independance Day--"Is there love? Then that's all you need--everything else doesn't matter." I beg to differ. Even though I've "felt" love--did I really, since I'm not sure what it really is? Is it an emotion? Feeling? A choice? Made up in our earthly mind? Currently, I'm almost leaning towards the latter, but I think in my heart of hearts, it's more of the first 3, mostly #3. Which begs the question, if it's a choice--then why does it hurt so much when "love leaves?" In turn, that's why I think it's an emotional response to the other person. But what if your emotions are all over the board and you cannot grip the feelings from them--what then?
I know God gave us free-will so we could choose to love Him. So it's a choice then?? If it's a choice, then how do people "fall in love"? That would seem to indicate it's some hole that we fall into based on emotions. Circular argument--what if your emotions are wacked. I've talked with several people on this getting several responses deriving the synopsis that I need to define what it is to me--aww crap. Perhaps.
My beliefs at the moment say to me that love is a choice as well as an emotion and feeling. I don't really know how to explain the emotional/feeling side of it that well w/o it sounding needy or possessive, but a choice. The choice to love someone. That would seem to leave a lot of room for failure based on other choices I've made and then changed. Ooh, that would be damaging--change love to not love...umm. I suppose it could happen--and probably does. For me though, I think the choice of love is more related to current, daily life. I choose to love Ms./Mrs. YYY today because of X,Y,Z. In an argument, I still choose to love her because it's that love that binds us together more. Tough love I suppose. The choice to love someone even if they've hurt or offended you--I think that is more the choice. Stick with it or run from it. Granted, not all love is tough--there must be moments of "peaceful" love. (hopefully more than less) But I'm sure I've only sampled what love really is in this context. From the sample though--I sure would enjoy more of it--but, well--that choice doesn't seem to be offered at the present time. So now, I guess I get to meddle with the thought of it--choice. Emotion. Feeling. All three are related I think--but what is it really? I've felt anger--I know that one; really wanted to rip someone's head off--I get that. Maybe I attest too much faith in love--like some magical glue that'll hold the relationship together; well, like I pointed out--that bond broke twice (maybe I need stronger glue??). Not really 100% sure--pretty sure it exists, since God is Love and He created it--it's out there--somewhere. Anyone know where I can find it?