@pettdan answered well.  Nissa, VF is probably the most popular right now.  Does everything you want in pretty much every matchup.  Haste-kill Jace, quick damage against combo / recur disruption pieces when applicable, card draw in grindy games.  I've been running a couple lists that have 2 and she is bonkers.
I've been more and more impressed by Nissa Vastwood Seer the more I play her now that I'm getting back into non-Nyx builds.
Garruk Relentless became a lot better after the walker change - you can play multiple a lot more easily since you can have both sides out at the same time.  Shoot down a deathrite, start making 1/1's and you can play a second copy.  He was the sort of go-to combat walker when needing one against Miracles.  Junk has access to Gideon now which is a pretty similar role.  Ditto with small Elspeth.
Elspeth, Sun's Champion is probably the best 6-drop if you are in white.
I've got a BUG walker fit list somewhere with both Jace TMS and 
Nissa, Steward of Elements.  Really want to try those together since you can Brainstorm with Jace to setup a creature on top and then get it into play for free (and uncounterably) with Nissa.
Liliana, the Last Hope definitely fine in an elves or D&T-heavy meta.  I've not tried her extensively for general use.  Compliments a recursive, graveyard focused deck such as one with Meren / Loam shenanigans / Intuition / Recurring Nightmare.
Or just play them all.
4 Veteran Explorer
4 Deathrite Shaman
1 Eternal Witness
1 Nissa, Vastwood Seer
4 Cabal Therapy
4 Oath of Nissa
2 Collective Brutality
1 Gideon of the Trials
2 Liliana of the Veil
1 Liliana, the Last Hope
2 Gideon, Ally of Zendikar
1 Garruk Relentless
2 Garruk Wildspeaker
1 Kaya, Ghost Assassin
1 Ob Nixilis Reignited
1 Nissa, Vital Force
1 Garruk, Primal Hunter
1 Ajani, Mentor of Heroes
1 Elspeth, Sun's Champion
1 Garruk, Apex Predator
1 Karn Liberated
2 Ugin, the Spirit Dragon
3 Forest
2 Plains
2 Swamp
1 Phyrexian Tower
1 Ancient Tomb
2 Bayou
2 Savannah
1 Scrubland
4 Verdant Catacombs
3 Windswept Heath