There are some named generic delegates that promote readability, especially when used along with anonymous methods. Here's a list of such delegates which reside in the System namespace:

Action: http://msdn.microsoft.com/en-us/library/system.action.aspx
Action<T>: http://msdn.microsoft.com/en-us/library/018hxwa8.aspx
Action<T1, T2>: http://msdn.microsoft.com/en-us/library/bb549311.aspx
Action<T1, T2, T3>: http://msdn.microsoft.com/en-us/library/bb549392.aspx
Action<T1, T2, T3, T4>:http://msdn.microsoft.com/en-us/library/bb548654.aspx
Represent a method that performs an action (on the specified object(s)). This set of delegates accept 0-4 parameters and return void (as the name suggests).

Func<TResult>: http://msdn.microsoft.com/en-us/library/bb534960.aspx
Func<T, TResult>: http://msdn.microsoft.com/en-us/library/bb549151.aspx
Func<T1, T2, TResult>: http://msdn.microsoft.com/en-us/library/bb534647.aspx
Func<T1, T2, T3, TResult>: http://msdn.microsoft.com/en-us/library/bb549430.aspx
Func<T1, T2, T3, T4, TResult>:http://msdn.microsoft.com/en-us/library/bb534303.aspx
Encapsulate a method that has 0-4 parameters and returns a value of the type specified by the TResult parameter.

Comparison<T>:http://msdn.microsoft.com/en-us/library/tfakywbh.aspx
Represents the method that compares two objects of the same type. Accepts two parameters of type T and returns an int.

Converter<TInput, TOutput>:http://msdn.microsoft.com/en-us/library/kt456a2y.aspx
Represents a method that converts an object from one type to another type. Accepts a parameter of type TInput and returns a TOutput.

Predicate<T>:http://msdn.microsoft.com/en-us/library/bfcke1bz.aspx
Represents the method that defines a set of criteria and determines whether the specified object meets those criteria. Accepts a parameter of type T and returns bool (as the name suggests).