I play Garen against him - I bully him in lane, until 3 and then I just sit back and farm, every time I see a minion getting low I get back in his face and Q E him back. It's not about pushing the lane, it's about countering his farming.
That being said - you need to have a team that can survive with you having a solo top lane battle, because the worst thing any team can do is let a Nasus free farm top uncontested, because he will casually stroll down the lane and take towers like they are nothing. Alternatively sending the support or mid lane to kill him is bad also as even with a modest amount of stacks, a Nasus will tear squishies apart.
Nasus is a very balanced champ in my mind - he must farm to be strong, and that typically leads to abandoning his team or being under Q farmed - take advantage either way by pushing harder than the other team.