My favorites right now are Koba, Blue Eyes, and Caesar from Rise/Dawn of the Planet of the Apes. People have seen me rambling about these movies in lots of threads so I apologize in advance for yet more xD;
Koba - I think he looks awesome, which is what drew me to him originally. His backstory (elaborated on in the book Firestorm) is super tragic and completely explains why he isn't quite right. I feel like he was a well written character when they could have so easily made him a stereotypical villain. Up to a certain point I really think he had the best interest of the apes in mind with the information that he had available to him, but he crossed some lines for sure until he became a true villain by the end. I won't say more bc spoilers.
Blue Eyes - I LOVE Blue Eyes! He has such a rough dose of reality throughout Dawn and its portrayed amazingly through facial expressions and body language in a very internalized manner - until one part near the end where he breaks a little and expresses himself in a more obvious way than is typical, which shows just how much he went through and how it did affect him profoundly. He realized too late that he was idolizing and following the wrong ape and had so much regret that it hurt to watch imo. His breakdown, as contained as it was, still makes me cry when I watch the movie sometimes. He definitely redeemed himself by the end even though he was a little bit of a spoiled angsty little thing in some parts earlier on. Even my friend who was put off by his initial attitude adored him by the end. He's probably my favorite ape to RP even if Koba is my main tbh, but I'm more confident in my ability to portray Koba. Blue Eyes is difficult since everything /is/ so internal.
Caesar - I mean, what can you even say about Caesar? In Rise we watch him grow from newborn to near adult and the journey we watch him go on is as heartwrenching as it is inspiring and triumphant. In Dawn its even more heartwrenching and tragic because he had that happy ending that he fought so hard for, but then everything kindof exploded and got out of control. He learned some pretty painful lessons in both movies but he came out of it an amazing leader and I don't think any of the other apes that have been revealed to us in detail could have accomplished what he did, even if they'd had the ALZ from birth. That's not to say he's perfect, but he's pretty much THE ape. Do you know anybody else who can bring 2,000 angry apes back under control with a single word or a lift of their hand? Hail Caesar, man, hail Caesar.
Honorary mention is Ash. He had a heart of gold, it was obvious even if he didn't have a large part in Dawn. Plus, his freckles are adorable. I don't think I've ever heard of anybody not loving Ash. He's @
PenEvan's bby (which is super fitting bc Ash and Blue Eyes are best friends and so are we xD)
I have fan dragons of most of the named characters on the first page of my lair with screencaps of the corresponding ape in their info boxes~
(As for non-PotA characters, I like Toby Cavanaugh from Pretty Little Liars, Toothless from HTTYD, Henry/Terriermon/Guilmon from Digimon Tamers, and Godzilla [also known as Junior or Zilla Jr by the fandom] from the American cartoon Godzilla: The Series. I have fan dragons of Zilla, Charizard, Noivern, and two breeding pairs of Night Fury fan dragons)