http://github.com/gmarik/vundle         -- Package manager 

http://github.com/Shougo/vimproc        -- Required for ghcmod-vim

http://github.com/Shougo/neocomplcache  -- Completion

http://github.com/Shougo/neosnippet     -- Snippets

http://github.com/schell/vim-snippets   -- Snippets

http://github.com/scrooloose/syntastic  -- Syntax checking

http://github.com/scrooloose/nerdtree   -- File drawer

http://github.com/altercation/vim-colors-solarized -- Color theme

http://github.com/ujihisa/neco-ghc      -- Haskell completion for neocomplcache

http://github.com/tpope/vim-fugitive.git-- Git integration

http://github.com/kien/ctrlp.vim        -- Sublime text's anything command (quick goto)

http://github.com/Lokaltog/vim-powerline-- Status line

http://github.com/majutsushi/tagbar     -- Symbol goto based on ctags

http://github.com/kana/vim-fakeclip     -- OS X clipboard support

http://github.com/flazz/vim-colorschemes-- More colorschemes

http://github.com/eagletmt/ghcmod-vim   -- Syntax/compilation checking, quickfix integration

http://github.com/travitch/hasksyn      -- Better haskell syntax coloring

http://github.com/dag/vim2hs            -- More haskell syntax coloring

I have a lot of Haskell syntax plugins and some of those may be conflicting, IDK, but it works well IMO. Using all that I get a pretty good IDE feeling when developing in Haskell. I also use a tool called steeloverseer that I wrote to continuously compile my cabal projects. If you're interested it's on hackage and you can read the readme at https://github.com/schell/steeloverseer/. I hope that helps!