I chose Eclipse over Textmate earlier this year. As a user of mostly Python, Javascript, HTML and CSS, Eclipse has provided my ideal programming setup. All of my code, for all of my projects, resides on a development server of mine (Ubuntu). With Eclipse, I'm able to install the Eclipse software on my PCs and Macbook and am able to use the Remote System Explorer to edit my code over SSH. I then have the Aptana suite to provide the syntax highlighting and stuff. I close most of the unnecessary Eclipse GUI elements so I'm left with a very bare-bones feeling editor. So, my same editing environment works across all of my computers.

When I used Textmate on my Macbook and Notepad++ on my Windows PCs, I always had issues with indentations, and stuff from one editor to the next. I also used to have to setup Samba on my Ubuntu server to map the network drives, and edit them over a mapped drive.

Once I found Eclipse to be as awesome as it is, I don't think I'll ever look back. lol.