even though i prefer leona as a champion, in the support position my favourite has always been nautilus. He's got great engage and lockdown. Do realise, you'll most likely build NO damage and carrying becomes hard because of this. He's also quite weak right now, make sure to abuse the laning phase. Easiest hook in the game once you learn it's broken hitbox..
Fiddle, i've been playing it support for a while now, and it has recently become one of the best support picks so be sure to give it a shot. Your ult can easily secure a double and your poke is obnoxious as hell. Your fear is quite good peel but single target which you AND your adc need to keep in mind.
Poppy is an option too, though i play her jungle i have tried her as support with sucess. Great to counter dash champs like alistar or pyke.
Singed can be played support. Quick heads up, your team is either gonna love you or hate you, no inbetween. dont take this to ranked if you don't play alot of singed tho.
Annie is probably one of my best supports too but for reasons that might not be what you're looking for. let's just say i used to play alot of adc in blind pick and i don't take role stealing like a cuckboi, that's my doublekill now. either way you have great cc early on (lvl 1 double stun) and become quite a monster if you can get some items. she is also capable of beefing up with HP AP items if needed and i don't know the exact interaction but even abyssal mask can be used by her as she's quite deadly when she get's in your face.