Being called a 'rape apologist' isn't super fun, I gotta say. But one of my least favorite arguments against the pairing is definitely the fans that try to argue that I hate Buffy; "Why would you want Buffy to be in an abusive relationship with someone who she can never love as much as Angel?" Right. 
One of my least favorite things when it comes to shipping in any fandom is the idea that you can only judge a couple based on a previous relationship they had. We can't talk Spuffy without also talking Bangel or even Biley. My love of Spuffy doesn't exist in spite of Bangel or Biley, it has nothing to do with them (heh, see what I did there?), so why do Angel and Riley always have to come up when we're talking about Spike? (also, not saying only Bangel and Biley shippers do this, Spuffy shippers are guilty, as well)
One of my least favorite things when it comes to shipping in any fandom is the idea that you can only judge a couple based on a previous relationship they had. We can't talk Spuffy without also talking Bangel or even Biley. My love of Spuffy doesn't exist in spite of Bangel or Biley, it has nothing to do with them (heh, see what I did there?), so why do Angel and Riley always have to come up when we're talking about Spike? (also, not saying only Bangel and Biley shippers do this, Spuffy shippers are guilty, as well)