Two fragments of C# code I came across yesterday are currently on the top of my list. Here's one (I changed the names of the variables to protect the guilty party):
if (xxx != null && (false || (true && string.Equals(xxx.yyy,
I suspect I know how this came about... there may have been other conditions that got removed and instead of fixing the nested parentheses, they replaced them with constants. Still, that's how you make your code hard to read, hard to maintain and hard to understand. And hard doesn't equal "solid" ;)
And how about this conditional branch a few lines onward?
if (xxx == null) { return yyy; } return yyy;
I had a friend in my school wayyyy back when DOS and Turbo Pascal was the thing who did something like that to "make sure it gets done the right way"... as if the computer would decide to randomly skip a statement just because it is not written in double.
Bottom line: if changes to your code render parts of it useless - especially when they are THAT obvious - remove them! It will save you headaches in the long run!