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.