ok...this is my 1st time,so im stil a greenhorn,so dont blame me if i suck..=)
 
One of the greatest fears is of course yata garasu plus Chaos emperor dragon combo.burn everything around u together wif wotbf n sangan.search for yata.summon it n atk.this combo is almost unstoppable,but wad if... u had a searcher too?
 
another one is the exodia one.u can simply get the head into the graveyard n tts it.the only other way he has is to use recursion on it n use hane hane,gale lizard,or oenguin soldier on it,other than that,theres no other way.
 
gren maju de eiza is also a force to be reckoned with,together wif chaos necromnacer n shadow ghoul.u can actually make a deck centred around them,wif painful choice,card destruction,banisher of light,soul release,skull lair n gracefuls in ur deck.
 
another thing tt u woould hate is destiny board,although this rarely sees play.harpi n heavy n mystical n any m/t removal would fix it up=)
 
nowadays,many ppl play beatdown or control or chaos.to guard against beatdown,stock up on mirror walls,mirror forces,wabokus,zero gravitys,torrential tribute,or simply dark hole ,raigeki,fissure,trap hole.for control,i have nth to say except hand advantage.control decksmake use of the fact that u have very little cards in field n hand n start to unleash holy crap at u by using clowns,imperial orders,time seals,yata,jinzos to basically "control" ur every move.so juz stick wif cards tt gif u hand or field advantage.gracefuls,pots n searchers r recommended.for chaos,basically make sure they have no light n dark monsters in their graveyard.dark types r hard to stop,but light types are'nt.there r only magician of faiths,dd warrior lady,perhaps guardian angel joan n even more unlikely bewd,whot magical hats n magical merchant.juz use soul release,kycoo,book of life(if u run zombie) n stock on bottomless trap holes n ur set.
 
i actually thought of a new deck type,but it really sucks,so ikm not sure if any1 would like to try it.its basically a umi-dragon deck.the main cards r of course umi,umiruuka,dna surgery,gravity bindd tribe,legendary ocean,maiden of the aqua,those 1800+ water attackers n berserk dragons,bewd,trihead dragon,ultimate offering n koitsu.mother grizzlys r also recommended.u can use mother grizzly is to summon koitsu so tt u can destroy it n summon berserk dragon.wif all those annoying equips on YOUR side,ur gonna practcally kill ur opponent wif him.gravity bind is also recommended as ur fishes can attack under gravity bind wif legendary ocean.u can also use owls of luck,or searchers or amphibious bugroths to ur advantage.dont forget gagagigo,giga gagagigo,amphibain beasts.i hope this deck sees play=)
 
btw im from singapore n im 13.if u happen to live in singapore,duel me plz,im lousy=).my email is shadoweefurak9120@hotmail.com , send ur hate mail or comments to me.thx for reading my tip=)