10 scariest roller coasters in the world:

#10:
Sheikra - //Bush Grdens// (Florida)



#9
Kraken - //Sea World// (Florida)



#8
Colossus - //London Thrope Park//



#7
Manta - //Sea World// (Florida)



#6
The Incredible Hulk - //Universal Studios// (Florida)



#5
X-Flight - //Six Flag Great America//



#4
Top Thrill Dragster - //Cedar Point Ausment// (Ohio)



#3
Leviathan - //Canada's Wonderland//



#2
Millennium Force - //Cedar Point Ausment// (Ohio)



#1 (Tallest Roller Coaster Ever '139 metres')
The Kingda Ka