Joss owns Buffy and all of the affiliates, don't make me dwell. ;)
Hey, here's a little one shot I wrote in between chapters of Destination, Unknown (for those who care, aha).
Let me know if you like. :D
This is how I imagine Buffy's letter would have gone, had she written him one before she died at the end of Season 5.

Angel's hands shook as he unfolded the crisp white piece of paper before him. The train he sat on shook too, telling him that it was as nervous as he was. He pulled the curtain next to him down and checked to make sure that the man in the seat beside him was really sleeping; his heart rate and steady breathing confirmed in an instant that he was.

Taking a superfluous breath and making a conscious effort to steady his hands, Angel lowered his gaze to Buffy's distinctive handwriting. His breathing sped to substitute the acceleration his heart could no longer provide.

'Angel,

I hate to admit it, but if you're reading this I'm probably not here anymore. If the worst has happened - or, alternatively, I've cut my losses and eloped with Johnny Depp - I doubt you'll be hearing from me again.

There are a million things I want to say to you and five hundred thousand that I know I shouldn't.

I'm not sure what you're going through, but if it's anything like what I went through when I sent you to hell then nothing said here will help ease your pain for the moment, but we both know that I was never one to give up a fight just because I can't win.

Firstly though, I know that it's your thing to shoulder the blame for events that aren't actually your fault, so I'm warning you now: you spend one second blaming yourself for my death and I'll haunt you for the rest of your days. Or, even better, I'll send Spike to L.A. to haunt you for an eternity. Seriously. Spike. That even gives me the wiggins.

I hate to go all Socratic on you, but everyone always says that when you die, your life flashes before your eyes. I feel like my mind started early; some preternatural Slayer prepping, I guess. Like those visions and prophetic dreams that I get sometimes.

Speaking of, is it true that Cordelia has a connection to some higher power? I thought the only higher power she was connected to was the manager of Tiffany's,' Angel noticed that her hand had wavered here, probably from laughter. 'No, but seriously. Cordelia? I didn't know whether Willow was just teasing me when she told.

Cordelia!?

Okay,' she resumed, as - despite the circumstances - Angel felt himself chuckle, 'not the point. Sorry. I'm sure she's a,' Angel could see that Buffy had scratched out several amusingly inappropriate words before settling on; 'very nice person nowadays.

'Anyway, life flashing before eyes. What I was trying to say is that I figure if my life flashes before my eyes before I get to the Forever Young Slayers' retirement village in the sky, you should get to see it, too.

The first thing I'm listing here is pretty confusing to me sometimes: the day I was called. I always remembered that day, but when you told me that you'd seen me it was different. To imagine you watching me when Merrick found me - it's special. I didn't see you, I had no idea that you're there, but like a lot of times in my life, you were there when I needed it, you were a part of it.

Secondly; when I met you in the alley. I'd like to say that the drop down from the pipe and following kick I delivered to your head was the cause of much chagrin to me at a later date, but honestly I just thought it was kind of cool. Plus I never worried that I hadn't made an impression.

Three is -'

Angel thumbed contentedly through the pages, observing the quirks and nostalgia of the woman he loved.

Had loved. The woman he had loved. The woman that was now dead.

There were all the highlights of their relationship here, as well as the worse times. She'd essentially just written down an abbreviation of everything that she remembered about them, with quirky comments and side notes. On more than one occasion she had put a footnote in, defining some odd colloquialism that she rightly knew he wouldn't have understood.

'But everything has to end, right? It's okay. I accept it. I know that I only saw you once in L.A., well, twice, but the brief stop in after Thanksgiving doesn't really count -'

She didn't remember it. Their perfect night. She never would, now. Because she was dead.

Repeating it a lot, he realised, didn't make it easier on him.

'- but from what I saw, you've got a pretty good life,' Angel saw that she had crossed out 'except for Cordelia.'

The Slayer is supposed to die alone, and I guess I probably will - if Johnny Depp and I can't die in each others' arms at the tender age of one hundred and three - but I don't really feel like it. There are so many people around me, that I love, that care for me, and I love them all. And I love you. I probably shouldn't have written that, but hey, I'm about to save the world; cut me some slack, I've got major emotional baggage at the moment.

'I love you, even in death. You were always good at that,' Angel smiled amusedly,

'See, knew I could get a smile. Anyway, I have to go tell aforementioned people aforementioned feelings, which means that I can't write any more.

Kind of makes me wish I'd learned to email.

Yours always, in life and death,

Buffy.'

Angel let the tears roll down his cheeks. He folded up the note, making sure that it was in immaculate condition, and opened the window to gaze up at the stars. He still had a lot of road to cover, but he would do it; he would reach his destination.

He would do it with her song in his heart.