Build them old school my dude, pick a Clan and model them after their favorite strategy. But heres a few of the bigger ideas:
Stormboy Hammer, Kommando Anvil: 90 Stormboyz lead by Zagstruk, 30 Kommandos lead by Snikrot (all in 5 man squads with 2 burnas, cuz duh), remaining points in some Big Guns and a KFF Big mek for you anti vehicle and whatever else you'd like.
Green Tide: All of the boyz. Who needs vehicles when you can just drown your opponent in corpses? Sprinkle Banners and Warbosses to taste.
Kan Wall: The Kan wall is back and it works...well enough. Each Kan is backed by a KFF Big Mek (or a Gorkanaut) and then you through in Boyz (or Stormboyz) to taste.
Theres more, Biker spam probably still works and i know that the Battlewagon Brigade still does the only real hard nos are:
Lootas: These old boyz took us through the bad times, always there killing stuff for us, but they just don't cut it anymore.
Stompa: Its an overpriced mess that takes up half your army and requires the support of the other half to actually get anything done. Do yourself a favor and just run 2 Nauts (never thought it say that) or half a dozen Deff Dredds.
Everything else is either good or only overcosted a bit.