They look like syrphid larvae (or pupae?), especially how they are munching on the aphids. They are so tubby though! Hope you can get a real answer. :P

I think Fori is right. Had to take my dog to the vet and took a book. Came across this picture.

Oh, I think you nailed it, Fori (and thanks for the confirmation, Iris).

Found this pic on Whatsthatbug.com, and it's a perfect match to my pic #1:

Syrphid larvae/pupae are among the good guys. To them, I say: happy munching!