C# 2 did not have Linq. Linq is the best feature ever.
That's been the case for the majority of supposed "new features" in C# for at least the past 8 years or so -- LINQ, inline variables, anonymous functions, string literals etc. It's all just syntactic sugar on top of existing features.
So the real new feature in C# 3.0 are the expression trees. LINQ is only one place where expression trees are used.