I've found syntax irks in just about every language, will be a very long post if I had to cover all of them.
PHP, JavaScript and perl are the worst offenders, Python has some decent syntax, just don't like the whole whitespace indentation for blocks, Java's got too much boilerplate, C# and their usage of uppercase, Pascal and Delphi for writing everything out (eg begin and end instead of curly braces), Dart's optional type system causes some strange things as a result of of the optional type system (adding oranges to a list of apples under certain conditions apparantly is fine since they are both extending fruit), Scala and their loops, etc
Haven't been deep enough into Kotlin to be able to judge it fairly for irky behaviour.