1)Two-Face: My favourite Batman villain, I like his tragic origin and how writers seem drawn to try their hand at concluding his story. More than any other character I feel as if Harvey represents Batman's greatest failure. The fact that not only could he not protect his friend/ally but also have him become one of his greatest foes makes Two-Face always interesting to me. I also love the concept of his duality being inescapable much like Bruce's own in looking at his former comrade Bruce must see so much of who he is.
2)Joker: When written well he is often my favourite villain. However I find recent portrayals of the character as missing many of the facets I enjoy about his personality. I really dislike the attempts to make him more terrifying as I think that the Conrad Veidt look is much more horrific than the Glasgow smile/no-face looks.
3)Ra's: I enjoy that he represents a physical and mental threat to Batman. The idea that he represents an extreme version of what Bruce wants is extremely compelling. I also really enjoy how Ra's is not a Gotham based villain. The League of Assasins is probably my favourite villain organization in the Batverse and so I need to put their leader high on my list.
4)Professor Pyg: Horrific aesthetic and personality. Probably the most successful (and insane) villain from Morrison's run
5)Mr. Freeze: "This is how I shall always remember you: surrounded by winter, forever young, forever beautiful". Heart of Ice is enough to make Mr Freeze one of my personal favourites.
6)Riddler: Although Frank Gorshin really influences my choice I really just enjoy the character. I think he has a fun gimmick and great aesthetic. I actually liked him best under Dini's pen as a rival detective.
7)Talia: I know people didn't really love Morrison's take on the character but I think he helped make her one of Batman's deadliest foes (he negatively altered her character but showed her potential as an effective villain). I enjoy her femme fatale qualities and think that she is a much more interesting match than Selina Kyle. As with Ra's her ties to a shadow organization of ninja assassins really helps make her a great villain.
8)Dr. Hurt: The character is so unapologetic evil and sinister. Reading his story and trying to figure out his identity were great fun. I doubt that if he returns it will be as good but I will keep enjoying the character.
9)Penguin: Outside of Burgess Meredith's portrayal, I never had much of an affinity for the character but his mini-series and some recent appearances have helped make me reconsider the character.
10) Scarecrow: Cool aesthetic and concept. I really think that cool story's develop around the concept of him creating fear in his victims.
Special mention: Bane "who likes hip-hop"