Or anyone for that matter. Kind of hard to do anything against him when he chunks your health with a low CDR point-and-click nuke, high sustain from Consume and ridiculous lane freezing as a result. You can't outtrade him, you can't outfarm him and if you build defensively then you will do literally no damage when team fights happen. Help? Riot balance insight? Anyone?
Meep Man3 votesTo be honest, you cry. Thats about it.
Jasiwel1 votesYep, that's actually exactly how it went down.
stokastic2 votesI have to disagree when you say you can't outfarm him. Nunu's waveclear at any point in the game is just terrible. Play a ranged top laner like Jayce or Gnar or Vlad and you can stay away from his poke. If you insist on GP, I have no advice, I've never played him.
FatesDefiler1 votesdo a barrel roll.
Sachabot1 votesYou pressure elsewhere. That's about the best I can give you, sorry.
YumaS2Astral1 votesThere are some champions that can lane against 
Namely 
Cho'Gath is the best as he does almost the same thing as Nunu, but better. He can outpush Nunu, and his passive gives him enough sustain to compete with Nunu. If Nunu ever happens to ult, Cho'Gath can easily cancel it with his Rupture or his silence. Stacking magic resistance will also be innefective against the true damage of his Feast. EDIT: Oh, Cho'Gath can also use his Feast to contest objectives, just like Nunu can use his Consume, but Cho'Gath's Feast is better at taking Dragon and Baron due to its higher base damage, but Nunu's Consume has a way lower cooldown. Regardless, Cho'Gath can also beat Nunu at the "objective contest" part.
Mordekaiser also works, mainly due to his passive, which is a shield that allows him to take iceballs a lot better. He can also outpush Nunu, and after a Hextech Revolver, can outsustain him too. There are two problems, though. First, Mordekaiser will hardly be able to kill Nunu late game. Even if he outtrades, Nunu will simply Iceball him and flee. Second, Mordekaiser can't interrupt Nunu's ult.
Vladimir is there too, he will have to play safe but he can survive the lane phase against Nunu instead of being utterly beaten. After a Hextech Revolver, Nunu should not be able to do anything against Vlad. You can outsustain him, outpush him, and even if Vlad can't interrupt Nunu's ult, he can use his pool to avoid any damage, you have to time it properly however.
Other champions that I think that could be able to lane against Nunu but I've yet to test it to know: 
In general, you want to use a champion that has sustain or a strong shield, and that can outpush Nunu. For this reason I think that 
could also be a very good counter to Nunu, but I am not a good Riven player; however I've seen a Riven x Nunu matchup before. Riven lost the lane hard early but after a few items she could outduel Nunu and he couldn't escape even with his Iceball due to her constant dashes.
SaltyKracka1 votesFarm with Q and E, build slightly tank and heal off ice balls with W.
Realize that Nunu can't actually kill you and scales terribly. Ignore him.
Critmaster Garen1 votescan someone explain how I lane against Nunu...
you dont.
you just bend over, take what you can get in cs and outscale him eventually in teamfights. hes probably onbe of the strongest laners in the game and pretty much immovable due to his sustain. but he doesnt have much else to show for himself.
thats why lane nunu is never played even though hes ridiculously strong in lane. just take what you can get, recall if you need to. even if hes 50 cs ahead, he wont be able to do much with it.