Shaco and shyvana are the only two i can think of who usually don't take flash. This summoner is a must have on basically every champion and is reallly stifling to the meta. Same thing for TP on top laners
Ralanr3 votesSo...Flash is the Thresh of summoner spells.
Marthian2 votesAnd currently too ingrained and too necessary to be nerfed or removed.
Taking it out will currently screw up immobile characters absurdly hard and would require a lot of buffs that'd turn a lot of them into basically all-ins since they get caught out, they will have NO escape. It's a bad idea to think of taking Flash.
luckmallory1 votesTeleport Ignite on Fizz
Smite Ghost on Udyr
Ghost Ignite on TF
Exhaust Ignite on Janna
There are plenty
FacerollKatarina1 votesteleport ignite on fizz was bruiser fizz which is no more
luckmallory1 votesI still do it on mid fizz. Also TP Ignite on Trynd is really popular and for a while when i just played trynd i didn't ever take flash
Jbels2 votesTeleport Ignite on Fizz
Smite Ghost on Udyr
Ghost Ignite on TF
Exhaust Ignite on Janna
There are plenty
7 or 8 isn't plenty. There's pretty much no excuse not to take flash on the majority of the roster
luckmallory1 votesI could name more i just didn't want to go through the entire roster
Deep Terror Nami1 votesHecarim does it too on occasion. But there's no real problem with it. If Flash were, let's say, made a default spell on everyone, then another one would take its place as a staple spell.
Axxuka1 votes
Please
Mannysmoker1 votes
I could keep on..but the list gonna be too long
BeatinWarDrumz2 votestf needs flash...
Meep Man1 votes
You can also not run Flash on about any Jungler since its main use is to get out of deadly early ganks. Late game it's more for very limited plays that could have just been done easier if you had picked a champion with a dash.
Takhuan1 votesEkko can very effectively skip on flash.
Jungle wukong without ghost is actually not as good.
Penguin Eclipse1 votesLeBlanc does extremely well with Teleport/Ignite. Flash makes flashier plays but if you carefully use your W/R it is extremely rare that you actually need it. Taking teleport gives her nearly unlimited mobility, anywhere. In many games that can literally be a game changer.
Lord Azır1 votes
Marthian1 votesThis summoner is a must have on basically every champion and is reallly stifling to the meta.
Which is why it CANNOT be nerfed or removed. Immobile champions would be screwed with out it (and the only way to make it not so is basically reworking ALL of them into champions that can deal with being dived upon.)
4ManVotedAgainst1 votesI don't bother with Flash most of the time & still manage to win a majority of the time without Flash anyway. You need certain spells/items for certain reasons, for example, you need a Haunting Guise (or Morellonomicon) to deal with ridiculous Regeneration-Rate Healers, you need Mercury's Treads against a High-CC Team, you need Banshee's Veil against Diana-players, and you need Flash if you take risks that could put you into a pinch that requires that type of escape.
I, personally, rarely take such a risk, and therefore, I have not found many occasions where Flash was that much of a game-changing spell to obtain a win. I do take Flash if I go ADC but that is usually the only Role where I will bother to take it as a Summoner-Spell. I am split half-and-half between Flash/Teleport if I'm using Galio depending on the enemy team-composition.
Here is another funny thing, when people complain about me not taking Flash-spell, they often perform worst on my team, yeah, dogmatism over-powered.
Vicarious1171 votes 
They can all take ghost, or exhaust/ignite for some of them, over flash and be just as successful in just as many situations. Yeah in many cases people still prefer flash on all of them, but that doesn't change the fact that they can all effectively use a summoner other then flash.