If you're in search of a photo/image editor, this thread should be able to help you find the one you'll like.
There are many photo editors, they differ in their capabilities, performance, price, operating systems support and so on.

Software listed:

- Photo/Image editors paid
- Photo/Image editors free
- Raw Converters paid
- Raw Converters free
- Raw Converters - manufacturer's own paid
- Raw Converters - manufacturer's own free
- Image viewers and organisers paid
- Image viewers and organisers free
- A few interesting freebies for various needs



Photo/Image editors paid:


Adobe Photoshop
[link]
Yes, THE Photoshop.
Tutorials:
Tutorials for Photoshop can be found all over the web via Google.


Adobe Photoshop Elements
[link]
Little brother. Fairly capable for the price.
Tutorials:
Some of tutorials for Photoshop can be also applied to Photoshop Elements. Again, Google is your friend.


Corel Photo-Paint
[link]
The companion. Come in CorelDRAW Graphics Suite. It used to rival Photoshop and still holds its own.
Tutorials:
For this one, tutorials are pretty difficult to find sometimes.


Corel Paint Shop Pro
[link]
They say it used to be speedy. It's one of the best values on the market of photo editors. Recent versions (at least X2) can open some raw files too. Jasc used to make this one.
Tutorials:
[link]
[link]
[link]


Ulead PhotoImpact
[link]
I haven't tried this one much, but it's similar to Paint Shop Pro and Photoshop Elements in many ways. Ulead used to make it.
Tutorials:
[link]
[link]


PhotoLine
[link]
Looks very good on paper. The way it works is a bit odd, but it's fairly fast and probably only takes getting used to.


ACD Canvas
[link]
Not exactly a photo editor, although I've only tried an older version, it could have improved a lot since then. It's a pretty versatile tool, though, so it might be worth a try.
Tutorials:
Google's your friend here as well: [link]


ACDSee Photo Editor
[link]
An interesting photo editor that could use some more polish (I had some trouble finding a duplicate object button in the 2008 version).
Tutorials:
Google's your friend here.


Serif PhotoPlus
[link]
Not very well known, but it gets decent reviews.



Photo/Image editors free:


the GIMP
[link]
Probably the best free photo/image editor available.
Tutorials:
AS they're not that easy to find, here's my list:
A GIMP fire tutorial [link]
GIMP guru tutorials: [link]
pixel2life tutorials: [link]
A user group site: [link]
Gimplogy: [link]
Bits about the GIMP: [link]
A few nice brushes for the GIMP: [link]
Talk about the GIMP: [link]
Video tutorials by Jimmac: [link]
Official GIMP documentation: [link]
How to create a resizable brush in the GIMP: [link]


Paint.NET
[link]
It's decent if you install a bunch of plug-ins.
Tutorials:
[link]
[link]
[link]


PhotoFiltre
[link]
Not bad for some quick editing.
Tutorials:
[link]


Serif PhotoPlus 6
[link]
It was a bit slow every time I've tried it, but not everybody has that problem. It's not too bad, although a bit basic.


Photoscape
[link]
If yo want something simple that can also convert raws, this could be it.



Raw Converters paid:
I'm not sure there are any tutorials needed if you know your way at least with Photoshop Elements, the GIMP or such.


Adobe Lightroom
[link]
The youngling. It's been pretty slow on my PC, but the results aren't bad if you don't apply sharpening at higher ISOs.


Apple Aperture
[link]
Probably one of the reason Adobe released Lightroom. I've never used it, as I don't have an Apple PC.


Phase One Capture One
[link]
Capture One 4 is quite nice. Speed is OK, so is conversion quality.


Bibble
[link]
Speedy when it comes to batch conversions, conversion quality seems to be on par with most of the other converters. Available for Linux too.


SILKYPIX Developer Studio
[link]
A bit slow and the output quality isn't the best you can get (but still OK). It's pretty easy to use, though.


ArcSoft PhotoStudio Darkroom
[link]
It has most of the basic tools, might be good for beginners. Output quality was OK. It's no speed demon.


LightZone
[link]
This one has a different approach to handling exposure tweaks. It has the basic tools and some quite interesting advanced features. Runs on Linux and Mac OS X.


ToneUp S3
[link]
For Nikon users only.


DxO Optics Pro
[link]
They claim its output quality is one of a kind and some people seem to like it a lot. I wasn't very happy with its output, though.


Picture Window Pro
[link]
I haven't used this one, but its specifications are interesting.


Helicon Filter
[link]
It's a very easy to use tool, the price isn't too high and results can be decent.


RAW Developer
[link]
Mac OS X only.


Adobe Photoshop and Adobe Photoshop Elements with Adobe Camera Raw plug-in
[link]
I've listed this combo in the paid section of raw converters, because while the plug-in can be dowloaded for free from Adobe's website, you still have to pay for Photoshop/Photoshop Elements.



Raw Converters free:


RawTherapee
[link]
Quite nice. You can find a mini review of it by me here: [link]


UFRaw
[link]
It's a pretty good tool. What I like best about it is the way it handles whites. Colour transitions usually seem nice and smooth, very pleasant. Comes with a plug-in for the GIMP.


RAWHide
[link]
A youngster, but already has some interesting features, namely batch processing and conversion algorithms.


dcraw + batch scripts
[link]
It's a command line converter that works well with batch scripts and sometimes serves as a reference converter for other converters. You can find a tutorial how to use it here: [link] There's software that builds on it. You can find a list of that software on dcraw's homepage. There are also several GUI frontends for this neat tool: [link] .


s7raw (for Fuji cameras only)
[link]
Conversion samples combined with a tutorial: [link]


RawShooter Essentials
[link]
It's discontinued but for some owners of older DSLRs, it' a gem. It had a commercial version. Adobe bought them and later Adobe Lightroom was born..


SILKYPIX Developer Studio
[link]
A bit slow and the output quality isn't the best you can get (but still OK). It's pretty easy to use, though. The free version is limited in featuresa and isn't updated as often as the paid version.


Stepok's Raw Importer
[link]
A very easy to use raw converter that gives good conversion quality, although export speed isn't anything to write home about.


Rawstudio
[link]
An interesting raw converter for Linux.


Rawker
[link]
Mac OS X only.


Raw Photo Processor (RPP)
[link]
Mac OS X only.



Raw Converters - manufacturer's own paid:


Fuji Hyper-Utility
[link]
Fuji's own that has the extras.


Nikon Capture NX
Visit your local Nikon Downloads site.
Nikon's own that has the extras.


Olympus Studio
[link]



Raw Converters - manufacturer's own free:


Canon Digital Photo Professional
[link]
It should be on the CD you got with your Canon camera. You can also download it from Canon's website.


Fuji FinePix Viewer
[link]
It should be on the CD you got with your Fuji camera. I couldn't find a download link, if you can, please, send me a PM.


Nikon ViewNX
Visit your local Nikon Downloads site.
You can download it from Nikon's website (link above). It has superseded Nikon PictureProject.


Olympus Master
[link]


SilkyPix Developer Studio for Panasonic cameras
[link]
It should be on the CD you got with your Panasonic DSLR camera.


Pentax Photo Browser and Pentax Photo Laboratory
[link]
It should be on the CD you got with your Pentax camera. I have managed to find only updates on Pentax's website.


Samsung Digimax Master and Digimax RAW Converter
[link]
It should be on the CD you got with your Samsung camera. I couldn't find a download link, if you can, please, send me a PM.


SIGMA Photo Pro
[link]
It should be on the CD you got with your SIGMA camera. It can also be downloaded from SIGMA's websites.


Sony Image Data Converter SR
[link]
It should be on the CD you got with your Sony DSLR.
You can download it here: [link]



Image viewers and organisers paid:


ACDSee Photo Manager
[link]
Half legendary, but not a myth. ACDSee used to be copied by other programs both in UI and in functionality for years.


Zoner PhotoStudio
[link]
An image viewer that got a few simple image editing capabilities in its more recent iteration.


Corel MediaOne Plus
[link]
A media organiser, not that well know, but it can manage images as well as videos and aply some quick edit to images.


Camera Bits Photo Mechanic
[link]
Comes at a price, but some people love it.



Image viewers and organisers free:


Irfan View
[link]
A very nice and fast image viewer. Free for non-commercial personal use only!


FastStone Image Viewer and FastStone MaxView
[link]
FastStone Image Viewer mimicks ACDSee's interface a bit, MaxView is more like a pure image viewer and it does that job well. Free for non-commercial personal use only!


XnView
[link]
ACDSee style image viewer. Free for non-commercial personal use only!


FuturixImager
[link]
Simple and fast image viewer with some image editing abilities.


P3dO Explorer
[link]
Not bad one either, a bit of ACDSee style is in this one too.


Google Picasa
[link]
A popular photo organiser that also has some image editing capabilities.


Microsoft Windows Live Photo Gallery
[link]
A photo organiser, fairly simple again, it also has some image editing capabilities.


Photoshop Album Starter Edition
[link]
A photo organiser, fairly simple, but it could be enough for some, it also has some image editing capabilities.



[size=20]A few interesting freebies for various needs:
[link] -> Microsoft Pro Photo Tools, with links to RAW codecs download
[link] -> various utilities for editing photos
[link] -> Preview Extractor (extracts jpegs from raws)
[link] -> Free Digital Camera Enhancer

An article listing and testing various noise reduction programs: [link]


I would also like to add a warning.
It's about Pixel: [link]
I have bought that program more than a year ago and so far it looks like it's half-dead.
Feels like a scam, although it probably wasn't intended to be one.
The program is developed by a single guy and he sucks at keeping promises and dates more than I do... which mean he's like the devil's own .
There was supposed to be a final stable version almost a year ago. Instead, he kept on adding features and what's available now is incomplete, buggy and not very stable either.
It was a very disappointing purchase.


Unfortunately, I can't help much with Mac software
I can update this thread with suggestion later on, should you have any.

If this list seems to be familiar, it's because you might have seen it on [link] or cameralabs.com forums.