I specifically want to talk about Allistair, and the weird, depressing path that my romance with him took. Of course, you know that if you aren't playing a human noble female, your relationship with Allistair will turn somewhat sour if he is made king. I'd actually read about all this beforehand, but I still decided to take that route. Later on, after it was too late, I found out that there are ways to circumvent this by "toughening" Allistair up. During a conversation after he meets his sister, you can basically give him the "tough love" speech, and tell him that everyone is out for themselves, and he'll start to grow more of a backbone. Unfortunately, like I said, it was way too late for me to go that route. 
 
I contemplated making the Loghain switcheroo, out of spite, but I didn't have the heart.
 
By the end of the game, with our relationship in pieces, and both of us acting kind of cold to one another, it came down to actually killing the Archdemon. I'd outright refused Morrigan's offer (seeming really weird that there wasn't the option to have Allistair get your character pregnant, but I'd imagine that has something to do with Morrigan's plans for the baby), so it was either Allistair or me who had to die. I tried to take the blow myself, mostly out of spite to get back at the bastard for dumping me. Of course, he wasn't having it, and launched himself at the Archdemon.
 

So in the end, my long, heartfelt relationship came to an end, anyway, though I'd always known that it would happen one way or another. My character gets screwed over on every love interest in the game. Despite every effort I make to keep Jowan from punishment, he's locked away. Allistair bites the bullet after talking about having another woman's baby. Morrigan, who had earlier in the game declared my character her best friend, leaves on a whim. Both Shale and Wynne run off on their quest to return Shale to her dwarven form (there goes my mentor and companion).  
 
The only one who really stays by my side is Zevran, probably hoping to catch me on the rebound now that I'm single (and I found it funny that, when asking if he wanted to become a Grey Warden, he says something along the lines of "There are some bodily fluids that even I won't touch"; furthering the stereotype that elves are the slut race of high fantasy).
 
So now I've got the Morrigan shady ending and the Grey Warden leader ending, and if Bioware expects me to go after another one, well, they're dillusional because...