You know what part I actually liked that a lot of people hated and thought was pointless? Quentyn Martell. I actually was giddy WHILE he was dying, for three reasons:
A) It was a nice switch-a-roo, making us think Quentyn would be a player in this game when really he wasn't at all. (Which also kind of mirrors Oberyn and the Martells in general in that they just can't catch a break. Though if the Sand Snakes don't end up doing SOMETHING that contributes to the plot, the Martells will officially become a running joke.)
B) It gave an excuse for the remaining two dragons to be set free at (what I thought) was the worst possible time...though in my opinion Martin kind of ruins this by having time pass and people go "Oh yeah, those dragons? They're hanging out over there, its kind of annoying" rather than having them oh say go on a RAMPAGE and burn EVERYONE.
C) It quite clearly demonstrates that not just ANYONE can tame a dragon, or even get close to one, which (and this is the MAIN reason I was getting giddy) I thought was to make us REALLY nervous when one of those dragons approaches Tyrion...only for Tyrion to be able to tame it! I mean, Martin really foreshadows Tyrion's love of dragons quite heavily early on in the book, and I was looking forward to say...one of the dragons going after Penny's pig, Penny being stupid enough to try and save it, Tyrion being brave enough to try and protect her, and somehow being able to STOP said dragon. I mean, if Tyrion showed up in front of Dany RIDING one of her dragons, there's no way he won't have her unconditional trust. So really, THIS is what I thought was going to happen, and who knows? It still could!
Apologies for the rant/speculation.