Top
Archetypes: Tanks, ranged casters, sometimes assassins, and rarely ranged AD glass cannons.
It's hard to go wrong with a tanky top, but having one of each helps and can overlap with your other positions too.
Ideal Pick: Rumble - As a strong damage-based caster with good initiation, if you can play Rumble top, he fits in pretty much any meta and team composition.
Easy Picks: Malphite, Sion - Big initiation, decent sustain (shields), hard to kill.
Mid
Archetypes: AP or AD burst champions, sometimes ranged AD with an escape and burst
Most AP mids tend to be more consistent, except when Talon is in cycle.
Ideal Pick: Morgana or Kassadin always cycle around eventually, and are fairly easy to pick up.
Easy Picks: Malzahar, Morgana - Easy and safe waveclear, good CC
Jungle
Archetypes: Tanky initiator, assassin, hybrid bruiser
Tanky initiators tend to get nerfed less than the other two categories, since there's less to complain about.
Ideal Pick: Jarvan IV - Always cycles around eventually with his high CC and free team stats
Easy Picks: Amumu, Nautilus, Xin Zhao - High CC, large AOE skillshots, high health jungle clears
Support
Archetypes: Tank, Healer, Burst Damage
Choosing a support depends on playstyle, most supports are fairly balanced.
Ideal Picks: Sona, Leona
Easy Picks: Sona - Heal, Poke, AOE CC, Sick Skin
Marksman
Archetypes: Burst damage, Poke damage
Marksmen cycle very often, but most of the ones with some sort of escape tend to be better in more situations.
Ideal Picks: Graves, Corki - High AOE, good escapes, good waveclear
Easy Picks: Caitlyn, Jinx, Ashe - Long range, ability to snowball even after losing lane using long range ultimates.
