I wouldn't call it the worst language in existence by any means, but it does have some things I find extremely irritating - lack of a decent module system, overly verbose at times (like when creating anonymous functions), sneaky silent type conversions that still get me from time to time (sorting a list of integers - oops, lexicographical, not numerical ordering).

Having said that, it also has a lot of cool features and I use it every day. Most of the time, I find it a decent enough experience.