Vim is great out of the box, but there are plenty of great plugins to extend the main editor, and provide tailored functionality for working with specific languages, frameworks & environments.
Pathogen should probably be the first plugin you install, as it'll make installing all the others easier. After that, have a hunt around & see what tickles your fancy...
Boilerplate code: Unavoidable. Now easy.
Find files, every if you can't remember where they are or what they're called.
List & choose from all your open buffers.
A huge improvement to Vim's built-in directory browser.
An easy way to make large, precise jumps within a buffer.
Easily manipulate surrounding quotes, braces, tags and more.
Extend % to match more than just braces.
Vim has a very sophisticated undo/redo model. Gundo makes it easy it use.
Easily switch between header & code files: .h <-> .c
Improved search & replace to handle mixed-case & plurals.
Clean, safe installation of vim plugins.