Below are some plugins which I believe may be very helpful for people installing Eclipse/PyDev (those are the plugins I usually install on any new Eclipse install).
Details at https://github.com/basti1302/startexplorer
Mostly, I use it to open the current file in explorer or copy the current file path to the clipboard (but it has other niceties too).
2. Extended VS Presentation plugin for Eclipse
Details at: http://andrei.gmxhome.de/skins/index.html
I use it for skinning Eclipse (i.e.: providing a better look and feel), but note it's only for Eclipse 3.x (Eclipse 4.x has a skinning engine builtin).
3. Eclipse Color Themes
Details at: http://eclipsecolorthemes.org
Note that if you're using the Aptana Studio editors, you don't really need this plugin as Aptana Studio itself has a theming feature which supersedes this, but if you're only on Eclipse/PyDev and other editors, this may be a nice addition so that you can apply the same colors for several editor plugins at once.
4. Practically Macro
Details at: https://sourceforge.net/projects/practicalmacro
Yes, I know, Eclipse does not have macro record/playback by default and it's a major shortcoming. Well, this plugin does cover most of the use-cases I have for doing macro record/playback (although it does have some weirdness sometimes -- in which case I usually just start notepad++ editor just for this feature).
Details at: http://wiki.eclipse.org/EGit/User_Guide
Note that Aptana Studio has its own Git integration (so, when I'm in Aptana Studio I don't usually install EGit). Although it can do many things with Eclipse, I use the Eclipse integration (either from EGit or Aptana Studio) mostly to have a quick way to know which files I've changed and sometimes seeing the history for a given file. For most of my work I like to work on the shell, usually using a tool I wrote in Python: https://github.com/fabioz/mu-repo which helps managing many git repositories at once from a shell (and showing differences I can edit via WinMerge) -- and sometimes I even fire http://code.google.com/p/gitextensions for exploring some git repository.
I was thinking a bit about this one since in cvs and svn I did everything inside Eclipse, but when it comes to git this trend didn't continue. I think it's mostly because the major thing for me is that the synchronize view wasn't available to me on cvs/svn and the EGit synchronize view is not as streamlined/fast as the other integration -- as I have the habit of reviewing all the code I'm about to update, and as EGit made that process a bit slower (and git is pretty easy to extend with scripting on top of it), I just went a different way this time (but who knows, if EGit provides a more streamlined/faster synchronize view in the future for my modus-operandi I may switch back to only Eclipse here -- but it'd have to beat the time in which I do things in mu-repo which fetches/diffs lots of repositories in parallel in a pretty fast way, so, I'm not sure how feasible that is).