what is the best way to compare two strings in c#?

I think if you want to compare for equality then the Equals instance method http://msdn.microsoft.com/en-us/library/c64xh8f9[^] of string may be better as it also gives options to account for Culture and Ignorecase as given here http://msdn.microsoft.com/en-us/library/system.stringcomparison[^]

If you want to compare to decide the order in which the two strings are to be placed and want to have options of Culture and IgnoreCase etc. then the Compare static method of string, http://msdn.microsoft.com/en-us/library/cc190529[^] is better

as the CompareTo instance method of string, http://msdn.microsoft.com/en-us/library/35f0x18w[^] does not provide those options.

The "best" (the term is used ironically) method is "=="; it makes semantic comparison. It is not redundant and is more readable. And System.Object.ReferenceEquals gives you referential comparison. By the way, you can define your own equality (this is often needed) for your type, and in this way using referential equality is the must, because otherwise you would have stack overflow (if you define Equals or "==" and use it in the definition, usually for comparison with null; do you need to explain why?). The semantic of ">" or "<" can be got using System.String.CompareTo.

Please see:
http://msdn.microsoft.com/en-us/library/system.string.aspx[^].

Choose those methods which fit your purpose.

[EDIT]

I almost forgot: semantic string comparison may be case-sensitive or not and depend on culture. I mean, in one culture two technically different strings may be considered equal, or one less then another, but the result could be different in another culture. See all the System.String.Compare method, see the reference above.

—SA