Embed images, or thumbnails with url's?

What is the preferred way to put pictures in a post on the forums? I personally like just embedding an image, but I noticed that if you use the insert images button, it wants to make a thumbnail with a link to the image. One way preferred over another?

OP

I like to post the whole pic in my posts but I do resize to aroun 1000x 800 or so before I upload so my pics load quick.

these new cameras take huge pictures and some threads I visit take forever when the original pics are sized 4000 x 6000.

everyone likes to see nice big pics no?