I use IrfanView, have done for many years. Recently I discovered PhotoScape, another freebie, which gives me a little versatility with frames/borders (that's how I got the oval ospreys on my desktop). I stick with IrfanView 99%.
I tried an old version of Photoshop in a recent mad moment: far too complex and OMG how expensive! I wanted it to enhance washed-out and grainy video, but that feature wasn't working anyway.
So !!! I've just taken the plunge and installed VirtualDub2, but am floundering with that, I think I need more plugins but can't understand the lingo, need more expertise than I have.