Geany is awesome. I've been using it for a few years now. Rather simple and no-frills, but with some plugins it works pretty much exactly how I expect a code editor to work and has all the features I need. A hearty recommendation from me as well.

I use geany for all my development needs at work ( PHP ) - but it's only an editor not an idea.
I tried and really liked Brackets.io, sadly it's it doesn't support live edit via FTP which makes it rather useless for the way I develop. ( Fireftp on the dev server -> open in geany, save auto pushes the file )

For C++ development I've stuck to Code::Blocks, mostly I suspect because it reminds me of Dev-C++

I've tried both Anjuta and Eclipse, but they both seem to think that they should taker over the organization of my files which I really dislike.

@stan: I believe that there is a geany plugin that lets you do project management, not sure how well it works.

I use Github Atom for HTML/Jscript and Eclipse for Java; I've dabbled in a couple of other languages and IDEs, but I'm not really proficient with any.

Another vote for Atom here, a few annoyances, but I find it to be less annoying than everything else I've tried.

I do almost everything in Geany as well. For everything from assembly to C++.

Emacs. I think it qualifies as an IDE but it's not just that. Getting to do email, bookmarking & notes, chat and so on in the same app and being able to modify absolutely everything and being able to write a bit of elisp every time you get an idea for something that would make your workflow smoother is amazing. I do recommend not sticking with the default keybindings for the most often used stuff though, taking inspiration from something like Ergoemacs is better.

I like QtCreator for C/C++ (earlier I used Code::Blocks, but that was too unstable for me, so I looked for something different), but I'm thinking about switching to KDevelop 5. For Python I have to use PyCharm because my university wants me to. When I did much with Java, I used Eclipse. For everything else I prefer a simple Kate (or gedit when I'm not on a KDE Desktop).

Quoting: liamdaweAnother vote for Atom here, a few annoyances, but I find it to be less annoying than everything else I've tried.

Last I looked at it it was mac only - tried it again today, so far I am impressed.

All off the ftp plugins are crap, but it at least understands gvfs ( even if I need to use nemo/finder to mount first ) not perfect, but it has a good chance of becoming my new daily editor

I do like Atom a fair amount, but also tend to use gedit for quick changes.

Komodo Edit (Free version of KomodoIDE) is nice, but a little heavy for my needs.