Question: Now I am using the pull-down menus to set `:TTarget`, `:TCTarget`, and `:TVTarget` to `pdf`.

I also tried setting `g:Tex_DefaultTargetFormat='pdf'` and `g:tex_flavor='pdflatex'`, but neither worked.

Thanks!

Answer: 
Set

```
let g:Tex_DefaultTargetFormat = 'pdf'
let g:Tex_MultipleCompileFormats='pdf, aux'

```

in your config file for vim (e.g. `~/.vimrc`). That works well for me here, using vim 7.3.3 on Arch Linux.
Add the following lines to ~/.vim/ftplugin/tex.vim (create the file if it doesn't already exist). 

```
let g:Tex_DefaultTargetFormat = 'pdf'
let g:Tex_MultipleCompileFormats='pdf, aux'

```

This is the same as [evnu's solution](https://superuser.com/a/186288/184674), but without cluttering up your vimrc.