[Flash], two flashes are better than one; remember you want to live at the back of the team fight away from harm so having two methods of repositioning oneself is more important than any other summoner spell.


[Exhaust], I really wouldn't bother taking it as your support should be taking exhaust not you; however if your support has taken something else take it yourself you NEED one in lane and you need one in team fights to use on the tanks that will try and dive you.


[Ignite], I generally take the most as the extra damage is useful for getting kills in lane and the heal debuff counters summoner spell heal which a lot of AD carries have been taking.


[Cleanse], If the enemy support has stuns (leona, taric for example) take it. Not dying in lane is another important part of laning and nothing's worse than seeing the dazzle come out of the bush followed by graves igniting and buckshotting you at level 2 basically instakilling you without you having anything to stop it with.


[Heal], I don't actually like this summoner very much, I feel that cleanse is far better late game and at avoiding situations where heal would be needed, also it's countered by ignite which has a lower cooldown, but if you're used to laning with heal take it, it's not a bad summoner spell, afterall heal baits do feel awesome.


Others, don't bother with them if in doubt take ignite