Beginner's guide: Which sync pair should you pity?
This post is a long post. It primarily focuses on EX Master Fair, or Pokefair select scout. It's not perfect and I may not have all the recommended sync pairs on this list. Really this is more of the questions I myself consider.
Please don't pick a Pokefair sync pair you already have. You can always candy them.
Anyways, here are the questions you should answer.
1: Did you get the featured Master Fair sync pair? (Skip this question if it is select scout)
If no, pity them. Why else did you pull on the banner?
2: Any favorites you really really want, and don't have?
If yes, pity them!! Even if they're non-meta, because faves >>>>> meta every single time. If having a certain sync pair will make you happy then definitely go for it!
3: Do you have 1996 Red?
Consider SS Iono for EX terrain, or SSA Elesa as a secondary damage dealer + keep up terrain. Chase can be an electric support if you don't have NC Blue.
4: Looking for a certain role?
If you need a good support, Carmine, Atticus, and SS Morty can fit on a wide variety of general teams. For any of the other roles, anyone released within the past year or two is probably pretty good, but see #5 if you want some for specific types.
5: What towers are you working towards? Or, what type you want to expand the roster of?
Sorted by type. This is based on Maelmc's tower doc. They have WAY more options listed than shown here, and you will need master fair sync pairs for tower. Below I just list the Pokefairs. Consider picking one of these if you are missing one for that specific role.
Normal: Palmer (physical, if no good academy Arven), Larry (secondary physical + status), Elaine (support)
Fire: SS Morty (support), SS Hilda (mixed striker), SS Red (special, though you might have him already from the victory road select), Mela (special), SS May (physical)
Water: CLAVELL (<333, physical, esp. if no good aca Brendan), Dahlia (mixed + status)
Grass: Carmine (support + status)
Electric: SS Iono (EX terrain), SSA Elesa (special + terrain), Chase (support), N (physical), SS Emmet (physical)
Ice: SS N (physical), Grusha (support), SS Silver (physical), Sina (special)
Fighting: SS Bede (special, REQUIRED), Eri (support), Rei (physical)
Ground: Rika (support)
Poison: Atticus (support), SS Roxie (special), Klara (mixed), Oleana (physical + debuffer), Emma (physical)
Flying: Anni Skyla (status)
Psychic: SS Lana (physical, required if no NC Hilda), Lear (special), SS Steven (special OR support, he can do either), Avery (terrain + special + hail for whatever reason)
Bug: Benga (EX zone)
Rock: Alt Selene (special + status, REQUIRED), SS Diantha (physical + zone), Alt Elio (support, esp. if no Anni Gloria)
Ghost: SS Ingo (special + status), SS Korrina (physical)
Dragon: Alt Leon (physical + status + debuffer), SS Brendan (support + status), SS Cynthia (special)
Dark: Giacomo (physical), Akari (physical + zone)
Steel: Poppy (physical + status)
Fairy: Lacey (basically required, EX zone + pseudo-support), SS Mina (support), Penny (support), SS Wally (special), Diantha (special)
6: Well, if I'm not doing any tower in particular, and I don't have any favorites, who do you recommend from there?
Any of the supports in #4, and also SS Bede because special fighting is very rare and he has good DPS and is just all around fun to use.
7: What if I already have all the sync pairs above for [tower]?
Work towards completing that tower, and identify other towers you would like to complete and pick accordingly.
8: Can't I just get another copy of [banner character]?
Honestly, only if you don't see anyone in particular you really want. It's better to get a new pair in my opinion, because you can always candy them.
9: When is the best time to pity?
After the 10th of the month (or 10 log-in days). On the 10th you get one random free Pokefair and it may even be one of them you thought about pitying.
10: I already have all the sync pairs for every tower, and have zero preferences whatsoever.
When in doubt, just choose whoever looks cool. Or pick a random number.
If you have anything to add, or any questions to ask, PLEASE do in the comments!