Three or four deaths were spoiled for me before I watched the show:
Ned's (though, that one seemed expected)
Robert's (I'd seen stuff with Joff being kinged, so Robert kinda had to be dead for that)
Ygrette (inadvertantly stumbled upon a gif of her death, though it did seem rather predictable anyway)
Possibly Lysa's (I saw a gif of Pyter pushing her off.  I knew the show's face for Pyter, so I knew he was pushing someone, but I didn't know who the woman was.  But since the Vale is a great place for pushing people to their deaths, and Peyter was headed that way when I was reading, so it seemed like it would be her, though I wasn't entirely sure)

Overall, I'm pretty happy with how few deaths were spoiled.  There are so many deaths that it can be so easy to mess up the story for someone.  I'm extremely happy that many came as surprises to me, such as Joff's death, which was such a sweet surprise, the Red Wedding, which was such a tragic surprise, and the battle betwixt the Mountain and the Viper was the most tense part in the book for me, that battle was super exciting.  And reading it as it unfolded without being cognizant of the outcome made it so great.

I like a lot how Ned is introduced bedhead someone, and for his death Ned is beheaded with his own sword, which all seems really clever.  Robb's death seemed fitting, although a shame.

Serio and Old Bear are my favourite dead characters.  Though in the book no one actually witnesses Serio's death, so I'm still holding out on some fool's hope that our dear teeth-clicking Bravvosi will come back somehow.  Old Bear was so cool, though.

I really don't much care for Asha or Theon though, like wow guys, get out of my life, I don't want to read about you guys.  In general, the whole Iron Islands part of the narrative seems like too much spice in the mix.  It's already complex enough as it is.

I like Jon's story a bunch, though I feel like the Wall is too disconnected from the rest of the story and the other characters, and I feel like it could have been more interwoven.

I have a similar feeling towards Dany.  Though I like her, Jorah, and Ser Grandfather, I feel like the the lore of Esos was just thought up as a kinda afterthought, without as much care and detail as Westeros.  The names especially feel clumsily made and ridiculous, as if they were made just to confuse us.  It's also even more disconnected than the Wall.

My top four characters are still alive (Tyrion, the Queen of Thorns, Hodor, and Old Bear's Crow).  I'm really happy about that.  They're all probably gonna die sometime, but it's nice that they've come this far.

I'm a bit annoyed though that George kicked Tyrion into the Esos story, as I don't like Esos as much, and Tyrion's my favourite.  I was hoping he'd join up with team Dragon and head back to attack Westeros and he and Dany would become best buddies.  But no, they're both stuck there for the time being.

The thing that most annoys me is that the Hound is dead.  I really did not want the Hound to be dead.  He was such a dark character, but I wanted him to live on.  I wanted him and Arya to become best buddies and work together towards some goal.  I'm especially mad that he died before he leaned of Gregor's death, which would have likely made him reevaluate his whole life's purpose and had a lot of room for some interesting character development, but instead that whole road has been closed.

However, in that one chapter with Jamie, Brienne comes up to Jamie and tells him how they need to save Sansa from the hound, though that's a whole mess in itself since she's supposed to be dead, Sansa's with Pyter in the Vale, and the Hound is supposed to be dead, so that whole thing right there is a jolly good mess and I'm not sure what to make of it and I shouted at George a lot for writing it.

I'm also annoyed that Arya and Sam have now been split off further from the rest of everything, only briefly crossing paths and now are in their own disconnected stories.  I get wanting to have a lot of stories with so many characters, but it's a little pointless if these characters are currently doing basically nothing that affects anyone else in the story.  In Feast for Crows almost no one died and almost nothing happened, and I'm bugged by that.

I also really don't like how George started giving the chapters weird headers like "The Prince in Winterfell" "The Soiled Knight" or "The Ugly Girl" instead of just putting the names of the characters.  It feels pointless and rather annoying, especially since that wasn't done originally and just randomly added in Feast for Crows  I liked it how it was.  It does make a lot of sense in places like "Reek though, as "Theon" would be rather spoilish.  But in many places it's just ridiculous and confusing.  Why can't we just have "Quinten" or "Barristan"? having all of those fancy names is bothersome.  I also don't like that a few characters get random one-off chapters, like that Knight or the Red Priest.  Ugg.  Why George!?

George seems to never properly kill off a character at the end of a chapter.  As of yet, every character who seems to have died at the end of a chapter from their own perspective seems to live or not properly die (Bran, Arya, Tyrion, others)  Sometimes this false death is reavealed rather quickly, but in some cases it may take a long time (in such cases as Theon, Catlyn, and Brienne).  So I'm going to throw a good guess that Jon Snow isn't dead yet.  Of course, he could easily die from someone else's perspective from his wounds, yes, just like Quinten did, but at least he's not dead for the moment.  Prologues and Epilogues are exceptions.  Those characters always die.