I need your help! Image size and compression?

Lately I have been adding lots of pictures on my posts and I've grown a bit concerned about image size. When I post on forums I use 600 pixels wide pics in a highly compressed .jpg format in order to minimize load time. Here however I have been posting large size pics with no compression at all. Do you like the large pics and the detail they provide or you'd prefer smaller pics that are easier to load? I'll give you some examples of possible pic sizes and compressions so you can better see what you'd like me to use:

Uncompressed large pic (what I'm using so far) - 1,994KB file size:

Large pic saved as a compressed .jpg file - 779KB file size:

Large pic saved as a highly compressed .jpg file - 366KB file size:

1200 pixels wide pic saved as a highly compressed .jpg file - 144KB file size:

600 pixels wide pic saved  as a highly compressed .jpg file - 84KB file size:

So there you got it. The same pic in saved in different sizes and file compressions. Please let me know what size and compression you feel is the better compromise between image quality and file size.