Here's a list of meta heroes as of 7.05, from high-winrate heroes, for the sub-2k bracket:
Carries:- Wraith King
- Chaos Knight
Supports:- Crystal Maiden
- Vengeful Spirit
Offlaner Farmers:- Abaddon
High Win-Rate Team Ideas for Sub 2k MMR
Safe: Wraith King + Crystal Maiden
Offlane: Abaddon + Venge
Safe: Ursa + Warlock
Offlane: Axe + Centaur / Spiritbreaker (basically, just cut the wave or crap on your enemies)
Safe: Chaos Knight + Warlock
Offlane: Omniknight (farming) + Jakiro (harass early with liquid fire)
Solo offlane with Jungler#4: Crap on their mid and their offlane
Mid: Axe (vs. melee mid) or Jakiro (vs. ranged mid) - this is "crap on their mid and push"
Safe: Spectre + Lich
Jungle: Ursa (ganks safelane at L3 with 1-1-1 build)
Idea: Spectre / Spiritbreaker give you a global presence, and Axe + Lich give you teamfight. A mid-Jakiro gives you pushing power, and shuts down their mid, or more teamfight (backs up Ursa).
#5: Maximum Healing, Greedy Lineup
Mid: Abaddon / Necrophos
Safe: Necrophos / Abaddon + Warlock
Jungle: Wraith King (a bit of a stretch, but can work with Vamp Aura)
Solo Offlane: Omniknight
Note: This is a very greedy lineup. Jungle WK is a bit slow, but worth giving up levels in the offlane so that Omni can get solo XP and a bit more farm. Midgame, your WK should never die, nor your Abaddon. You are low on stuns, so Necrophos should get a Rod of Atos or ultimately a Sheepstick.