Using Dotabuff's top heroes by winrate, I've once again put together some viable teams for pubs for patch 6.85.
#1: Top Tier, Balanced
Ursa, Abaddon, Lich
You get a bit of everything in this line-up; Roshan, Ganking, Healing, Teamfight.
This can be run as a 1-1-3 or 2-1-2.
Laning: I recommend Zeus mid, Undying (and Lich) offlane, and Ursa + Abaddon safelane. You could also jungle Ursa and solo Undying, leaving Abaddon+Lich in safelane, and use Abaddon as a third core.
Spectre + Omni + WraithKing
Spiritbreaker (solo offlane)
This isn't a teamfight lineup - it's a gank lineup with Spectre as lategame carry. Send in SB, Haunt in Spectre, and use Zeus ult to soften up targets. Omni can keep the tough melee heroes alive in teamfights, but you need to be ahead by this point, because your early teamfight ultimates are underwhelming. You also might be able to get away with a jungling Wraithking if it's a low-level pub (he's not a bad jungler with Vampiric Aura).
#3: Armor Reduction
Slardar, Venge, Witch Doctor
Elder Titan (offlane)
This is an armor-reduction team, focusing on physical damage. (Don't run this against Omniknight!).
Laning: I would run dual lanes on this if you're low-tier (ET + WD). You can also roam Venge from the safe tri-lane (also stacking for 'Dusa). Medusa is actually quite a decent mid with the changes to Mystic Snake.
Itemization: Slardar needs a Blink to initiate, to enable Earthsplitter, which sets up a really good Death Ward (enemies are slowed). Medusa's Gaze, if she's in range, can also multiply the physical damage taken.
Sven, Disruptor, Silencer
Queen of Pain (mid)
This is a team-fighting lineup, with a fairly nasty tri-lane. If you wanted to run dual-lanes, send Disruptor with Undying. Tombstone + Kinetic Field is quite strong.