Support is kind of dull because you're kind of this expected CC/heal bot that should always be bot lane to get your carry kills. At least when I learned of them after being a Lux Support main ~7 months or so. Playing her led to me picking up Ahri not because they're OP or whatever anime weeb you all call it, but more because I felt like I was playing and not just sitting in lane watching my carry farm. I could poke and harass and run around on the lookout for ganks.
Anyway, this is just me, but here's a breakdown of the supports or "supports" I play for the most part and why.
Extreme utility, poke, shield, lots of self-peel and peel
Great at disengage, can easily engage/re-engage, heals have a nice bounce mechanic that can turn a fight
Amazing engage, amazing peel, late game becomes this impossible obstacle to the enemy
Shield, peel, heal, lots of mechanical outplay potential. An amazing Janna can turn a fight completely on its head if you can manage where to toss a tornado and kite. Only time I really pick her up is if I'm second-to-last or the last pick and the enemy team is building a full engage comp.
Now here's a list of enjoyable picks, but why I may not always pick them up.
Heals, bonus damage, MS, game-changing ult. Super binary and simple, kills don't feel rewarding and more just the enemy was dumb enough to get in range of a Q and auto. High expectations that you can keep everyone's health topped off at all times.
Three year stun, pool of pain, shield that blocks magic damage and one hard CC ability, ult that slows and stuns. While nice to get that shield off on your carries, stuns don't really feel rewarding enough and half of the time people just walk out of your ult (realize that this is a common problem, point still stands that it doesn't feel like I'm doing much unless they're dumb enough to stay even if they have no flashes as they'll just knock me away)
Recently started playing him when we have a Jhin just because of the amazing Synergy. Whenever I'm playing him, I'm kind of going "La di do dee day" as, for some reason, I find playing him absolutely charming. He's amazing at picking out that one target and staying on him, but from experience his peel is alright and his stun is somewhat odd to use because the stun doesn't feel like it lasts the second/second and a half. It feels more like they're moving as soon as my anchor is lifted, but I could be wrong. In addition, he has sever mana issues.
"AHRI ISN'T A--" SHUT UP! I want to put this on here because I've started to play her as a support a bit more often for a change of pace and I want to feel like I'm making an impact on what people consider is meta. Anyway, she's got True damage on return of Q, Charm is easily the most free damage you'll ever get. Only issue is she's extremely mana hungry so any you land you better be getting the most out of it. Only times I'll ever pick up her is if I'm having a shit day and want to have stupid fun.
On to the champs I want to play, but inherent problems coming from the team itself.
He's super fun, but I can't trust my ADC enough to not die when I go to collect chimes. It's a shame I'd rather just pick up Lux or Janna instead because this guy is just tons of fun with his abilities. Heal seems really weak early game as compared to Soraka, Sona, and Nami
I really loved him before the rework mostly because he was a flipping Gem Knight and the theme of him was pretty cool. Now I want to pick him up and I never can get proper stuns off. Half of the time my carry feels absolutely afraid when I'm a bit forward just trying to get the stun off and harass.
Really, really, really, really, really shitty luck with this guy and I'm sad that I don't ever want to pick him up at all. Bought him with RP but cannot try to learn him at all in a real game as if I miss a hook, team instantly rolls over and dies. Whenever I engage, team books it out to leave me to die, and I know the lantern joke already but honestly that's the least of my worries. I want to make plays, yet team is either never there or will immediately abandon when I get the perfect hook/ult combo.
Finally, champs I DESPISE playing unless I feel a need to.
Heal bot, nothing more. Lane becomes extremely dull, nobody wants to protect me and I'm constantly yelled at when I'm apparently not healing 24/7 because she has her W on a 0 second cooldown amIright? Seriously, though, silence doesn't feel rewarding and never works, ult is a waste half of the time as my team gets burst down, and q doesn't do any real, noticeable damage even stacking 6 
Hook, knockup, ult instant kill....hook, knockup, ult, instant kill. Same issue as Sona in that he's so braindead boring to play, his ult does a crapton of damage and that's about it. I want to kind of work for the kill, not be able to 1 shot and then go "...what do I do now?"
Braum is UGGGHHHH -an ally has been slain- which is a common thing. I like him, but I go to save someone only to get killed instantly because everyone backed off. Perfect knock ups annnnnnd team stares at me. Feel like I'm always trying to proc the stacks myself half of the time.
Hopefully sheds some light into my playstyle when in the support lane.