I personally use PhotoImpact by Ulead. I have no less than 3 versions installed :3
3.2, released in like 1997. It opens like as fast as notepad, my dad got it in 1998 and I started using it then, and I've used it SINCE then.
10 - For when I need more modern effects/features like png transparency or animation =o
12 - Even newer effects and features and can also handle video stuff and shitty photoshop files, but almost as bloated as photoshop itself
I could upload any of the versions =o