Package Control

Essential. Install this and forget about downloading files, updating, … Choose to use or not every other plugin, but this one is mandatory. Just install it.

Soda theme

The best theme I've seen for SublimeText. It's really clean and elegant. Don't forget to use it's custom colors too!

SublimeLinter

Highlight potential errors using lint programs so you can keep your code clean.

SublimeCode Intel

Helps with autocomplete, allows jump-to and displays information of the highlighted function on the status bar.

SublimeRope [Python only!]

Add a lot of IDE-like features to python developers thanks to the rope library.

Git & GitGutter

The first one is a tool to integrate git commands onto the command palette, the second one inserts an icon in the gutter area whether a line has been modified, added or removed.

SideBarEnchancements

Add tons of functions to the sidebar contextual menu!

AdvancedNewFile

This is the best. Create a new file just with a key combination, no popups, no nothing. Just press CMD+ALT+N, write the full path -relative to your project path- of the file you want to create and press enter.

I use some other plugins, but this is my top. Do you use other really good plugins not listed here? Tell me!