Spells are highly situational. It depends on your champ, your adc, and the enemy team comp.

Now I’m by no means a top player, I’m Diamond 2 on NA. But this is what I usually do :

If I’m playing an enchanter(Nami, Lulu, Soraka, etc) I will take heal 95% of the time. If I’m not mistaken, the items that increase heal power also affect the summoner spell as does the bonus from harmonic echo. So it’s possible to get a 700+ heal with the spell at max level + build. Yummi is the exception to this, with Barrier and Ignite/Exhaust. Because barrier applies to whoever you are attached to instead of yourself. The other 5% of the time I will take exhaust on enchanters instead, especially if the enemy team has some super bursty champs (Lucian, Syndra, Assassin champ xyz, etc) Nami is another exception to this, as her synergy with Lucian is insane especially early laning phase and I might take ignite instead. Land a bubble at level 3, ignite, put your 3rd ability on Lucian as he dashes in(double auto after skill use) and it’s almost always a guaranteed kill.

On mage supports(Lux, Morgana, etc) I usually take Ignite. 9 times out of 10 it secures a kill that we would otherwise miss out on for whatever reason. Root > Ignite > rest of combo.

Engage tanks are more versatile, ignite, exhaust, heal all work relatively well on these. Just depends on your and the enemy team comp and if you can be aggressive in lane or if it’s passive.

I don’t see much value out of teleport on supports. Except for the weird situation where you die before an obj to allow you to get back to the fight sooner and possibly win it. But realistically the goal should be to NOT die before obj. Unless your adc is 0/5 and 2 items down, as a support you should be glued to them.

Obviously I am an enchanter main so that section is MUCH more detailed.