Best IDE for C#?

[K.I.L.E.R]

There is Mono, Microsoft VS.NET 2003 and #develop (short for SharpDevelop).

Which is the best one to develop only C# apps?

I assume VS.NET 2003 but I could be wrong.

 

[Diplo]

Difficult to say. VS .NET is, obviously, very slick and has intellisense, but it's also very bloated and slow. It's also multi-purpose, so isn't just aimed at C# apps. It has poor search and replace, but some nice features like code-hiding etc. One big disadvantage is that it's very expensive too.

Personaly I'd try out #Develop and see how that goes. I have only played with it a while, but it seemed pretty damn good. As it's open source it will keep getting better and become more feature-rich. It's also got a smaller footprint than VS. However, it may be buggy too. Also, it's kinda weird in that #Develop is written in C#

 

[Miksu]

I've only used VS .Net from those so I have to recommend that one.

Personally I like VS.NET, mostly because it is really productive. If you have the money, I think you can't go wrong buy picking this one.