There are many reasons why we love Phoebus. Here's a list where fans can add theirs.
001. His looks - some HoND fans might disagree, BUT Phoebus is very attractive for an animated guy
002. His hair - it's fun to draw, although it always takes me over ten minutes to get it right^^
003. His beard - he simply would not be loved that much without it. There's even a Phoebus beard fanclub at Disney Dream's board
004. His changed personality - I don't know anybody who loves the original book version of Phoebus (except the naive girls Fleur-de-Lys and Esmeralda) Disney's Phoebus is way cooler
005. His facial expressions - Disney animators did a great job. I've never seen another animated character that has such complex expressions. Well, maybe Frollo, but he looks angry most of the time
006. His armor - because I love knights :-) And it's so shiney, colors of the French king
007. His voice - sounds soooo sexy. Kevin Kline helped a lot to create Phoebus' personality
008. His sense of humor - hehehe some persons think that he is quite annoying, but I like his jokes. Always there to cheer up the situation. And we know he can be damn serious too
009. His courage - disobbeying Frollo, leading the fight against the soldiers who attack Notre Dame... do I have to add more?
010. His love for Esmeralda - he's truly in love with the gypsy, although he surely knows that they will have to face several difficulties because of their different social background. I believe nobody in medieval society except their closest friends would accept them as a couple
011. His tolerance - he doesn't think of gypsies as abnormal people. He gives money to the poor and the most important fact: he is not disgusted at Quasimodo's appearance and treats him and Esmeralda as equals
012. His horse - because Achilles is great and now's how to sit and heel^^
013. His mistakes - they make Phoebus more humanly. He is definitely not the superhero-like knight in shining armor you know from other stories.
014. His smile - it looks so cute... do I have to explain everything? ;-)
More coming soon. Add your reasons