This is the dominion meta, at least at high Elo (I'm +62 atm):
At top there are 3 or 4 archetypes:
1. Standard
AP Bruiser (Diana, Zyra, Brand (w/ sweeper shroud), Swain)
AD Bruiser (tankyderps IE, J4, Pantheon, Xin, Darius, Jayce)
AD Carry (glass cannon w/ an escape IE, Ezreal, Vayne, Corki)
Support (usually tanky IE amumu rammus malph etc)
2. Double AP
AP Bruiser
AD Bruiser
AP Assassin (glass cannon IE Fizz, Evelynn, Brand, Poppy,
Support
3. Double Tankyderps
AD Bruiser
AD Bruiser
AP Assassin
Support
4. POOTing
AD Bruiser
AP Bruiser
Tank
POOTERSS (high mobility back-dooring monster usually zilean, rammus, janna, or lulu)
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At bottom there are really 4 primary archetypical picks:
1. AD Attrition
Fiora
Xin
Jayce
J4
Rengar
2. AP Attrition
Diana
Fizz
3. Sustain/Push
Yorick
Urrdurr (Udyr with HP regen EVERYTHING runs pheonix, stalemates lane and pushes like mad)
Zyra (push all day)
Heimer (push all day)
Mundo (Urrdurr variant)
Soraka (QQQQQQ pushes lane to tower with global presence)
Nunu (consume everything, AS slow counters AD attrition, spell vamp quints + early revolver means your consumes give you 9 BILLION health)
4. Trollololol
AD Malz (kind of hybrid attrition, scary as hell, strong push, can't 2v1 and no potential if switched top)
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General Meta:
Summoners:
5 revives
bot takes garrison
support takes garrison
all other tops take either 2 exhausts 1 ignite or 3 exhausts
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If you have any other questions feel free to post or add me in game!
gl on the scar 
CnD Ânders