If you use a language, use the language.
Sorry.... string, int, char and long are part of the language. Int32 is just some detail of the underlying platform. The fact that C# and VB.NET very convienently map onto the CLR type system doesn't mean that all languages do. Using BCL types also takes away the flexibility only a high level language and its abstraction over the platform can provide. Mind WPARAM and LPARAM in Win16 (16bits,32bits) vs. Win32 (32bits) vs. Win64 (64bits). (For the younger amongst us, the "W" in WPARAM used to mean "WORD" as in "16bit processor word" and "L" used to mean "LONG" as in, ahem, "long" or "double word"). Been there, hated that. If a language can fix those problems for me by providing a layer of abstraction ... thank you, will buy.