Hmmm I after looking into things think that Black Mask would be a good candidate

Yeah, I think Black Mask would work best regarding the events of the last film

Well they've covered Killer Croc and Deashot in Gotham Knight so it is unlikely they won't be in it

Yeah because we have to think about which characters could help sustain a healthy plot: I think the riddler could and so could black mask, but poison ivy or mr freeze couldn't carry an entire film

It all depends on who was the best villian in the adam west tv series and also movies. I would say Poison Ivy. shes so vile and so beautiful

oh my gosh, bring em all back! lol. nah
LOOK! i have an awesome idea.....
bring back Catwoman played by Michelle Pfeiffer (obviously)
THEN bring in Angelina to play Poison Ivy.
think about that
THAT would make for an unforgetable Batman movie.

its going to be the riddler. without a doubt, either working with the police or against batman. now that hes wated everyone would be asking "who is batman?" a riddle. duh. and no poison ivy, no mr freeze, no croc, all of them are unrealistic. catwoman can not be in the next film because going from love interest to love interest is just unclassy. The black mask cant work because he was a friend of bruce and if he wasnt introduced yet he shouldnt be at all. I would say to have two face continue but the riddler works too well with the batman being waunted scenerio. I think two face would have to be alive because then batman would have killed someone which contradicts the whole previous movie. They could set up a dark knight returns scenario where batman retire after hes waunted for a year but comes back due to gangs calling themselves the jokers (possibly lead by harley). when he comes back the riddler could take over the plot line. not doing any crazy, sci fi stuff tho. just the battle of wits.

Why does everybody keep suggesting already-used movie villians?
It's about time for a fresh movie name. Deadshot would be perfect, he's a crime-fighting assassin who becomes an enemy of Batman as he's trying to be Gotham's new saviour.
Anarky a political anarchist (given the said political situation in Christopher Nolan's films he'd fit in nicely) similiar to V in V for Vendetta.

Id like to see Harley Quinn. And yeah it can work without Joker.

Maybe harl works a bland job paying for her degree in psychology and became head over heels for Joker yadada

After he gets ceptured she loses it and finshes what he started.

Meh I just love to see Harley