There are lots and lots of photo editing software, some are even freewares.

Can you tell us which photo editing software that you have used that is the most intuitive?

If there is another photo editing software package that you find most useful, please also tell us here.

Thank you.

GIMP, Paint.NET on freewares (but quite limited features)

on most uses, Corel Paint Shop Pro is better ...

for me, Photoshop is too high-end for my casual, day-to-day basic usage

paint.net for me...

Easiest to use: Google Picasa. (In my PC).
Most useful: Adobe Photoshop CS4. (In my Mac).

Yep , Photoshop is too high tech for some simple picture editing and not to mention how expensive it is.

I use FastStone capture most of the time , it can capture your desktop screenshot/video , add text ,caption and watermark easily.I will think of it as a simple app that work just exactly what it should do and take very little memory.
I use Ashampoo Photo Editor for more option in editing the picture , extract picture out of video.

Well all the app I use is more like somekind of rare species that you wont get to see or hear oftenly but I really think its enough for some simple picture editing.

Photoshop definately the leader of those picture editing.

Can't agree with you. It's not "definitely the leader". Yes, it's true that it's got the most functions/tools but can is it so intuitive that everyone knows how to use it, I doubt so.

Agreed with the Photoshop part. I only use it when I really have too much time to waste xD or trying to mismatch face parts of friends's pictures.

Paint.NET - FTW. It's like the MS Paint I have used when I was small and knew by heart and this one is like the FATHER of all MS Paints.

That's why Adobe have different editions, the most expensive one, Adobe Photoshop CS, the middle range one, Adobe Photoshop Elements or Adobe Photoshop Elements SE (sometimes bundled with hardware purchases), and for photographers, they got Adobe Lightroom which is based on Adobe Photoshop engine too. If you're always connected to the Internet, you can use Adobe Photoshop Express (free) by visiting the site here or if you're on mobile (with active data connection), you can try Adobe Photoshop Mobile (free) by clicking here.

Many thanks for the links you've provided.

You're welcomed.