I use a free cropping tool called JPEGCrops. Unfortunately, it only works with jpg format, but it’s great at what it does with jpg. It can be downloaded at http://ekot.dk/programmer/JPEGCrops/
The thing I like most about this is that I can choose exactly where to crop each individual pix. The one on the left is 2560x1920 and I want to crop it to 4:3. I can get rid of some unwanted background or simply get closer to a face by grabbing and dragging the handle to make it smaller, resulting in the 1337x1002 on the right. (Steve, I KNOW that’s beyond the 1000 x750 you recommend, but that’s a job for one of the batch tools you recommend.)
My crop just happened to end up at the center, but you have the freedom to crop to any size and any area of the pic.
It does have a lot of preset aspects including one for 4:3, but not one for 16:9. There is an advanced preference setting to add new aspect ratios, but I'm struggling to comprehend aspect ratios so I'm no help there. (Maybe someone could take a look and give advice.)
I hope these examples help some of you. There is virtually no help file but it’s easily learned. The major thing to remember (so you don't overwrite the original) is to make a new file for your cropped pics or go into settings and check to rename files. If anyone else wants to download and give it a whirl, I’m only a post away to ask for help (except for the aspect ratio mentioned above ).
PS: The pic was taken June 07 in Louisville, Ky of me and my friend Robley Rex, age 106, one of the few WWI veterans still living. He is truly an amazing man. http://www.cnn.com/2003/US/South/11/10/centenarian.veteran.ap/index.html