The first is my favorite "art-wise". I drew it and colored it all myself, and am quite pleased with how it came out.
The second I also drew myself, but I didn't spend time on the computer inking, or smoothing the lines or anything. But it's still cute IMO.
The last one is I think funnier and more clever, but it's not really my art. For the first two panels, I copied two different ones from the actual strip, and just changed a little bit - a facial expression, the words, a little bit of coloring. The last panel is all mine, but it's not high art....it's not meant to be though!