Ziggs always kills me when I don't even see him. How can I avoid his range and counter his amazing power? Last night his ult was taking 75% of my heath and kept killing me when I was in lane and he was in jungle.
Magic resist always comes to mind, but remember that all of his abilities (Except his passive, which is a next-hit effect) are skillshots so you can dodge them or stay clear of them. Try to walk around until he uses his Bouncing Bomb ability, which is his most reliable form of damage, and then initiate after it misses and back off again. Keep poking him to get him out of lane or kill him if you can.
Ahri and Vlad are a hard counter for Ziggs just like any champion who can sustain them self early will be. Zigg's harass may be strong but he's certainly trumped by champions who can merely heal themselves and continue on fighting. You can still lane vs the champions and CS well but you'll most likely start losing the lane very hard around levels 7-9 as they gain more sustain and more items.
Kassadin like other assassin champions is a real pain in the ass to deal with for non sustain squsihy casters which just Ziggs just happens to be. Ziggs can most likely keep up or beat Kassadin pre level 6 but as soon as Kass hits 6 that lane is over. Ziggs has no hard CC to stop him from harassing, and Kassadins passive allows him to absorb more punishment then usual for an assassin champion. Basically Zigg's will lose this lane due to being out harassed and out DPSed. He's a big nono for Zigg's to fight against.
Ziggs is a great champion if played well. If playing against a first time Ziggs, you will almost definately own them. However, against experienced Ziggs, all you need to do is be close to him and be constantly moving. If he misses his 'Q' then he is basically screwed if you attack. Someone with quick attack speed will be useful but when near Ziggs do not try to kill minions, he will easily kill you. If you see him you need to attack him, even just getting his health half way or 3 quarters full. If you do this he will not regain any health because of no life steal so he will be cautious of approaching you. Build magic resist and NEVER let him be higher level than you. If Ziggs gets all the kills and is op, that will not be an enjoyable game.