I've used some of The Cat's Meow stamps which I've had for ages - I like them because the images are clearly drawn and also have a sense of fun. Have a closer look at The Cat's Meow range as there's some really good images in there. The sets have a wide variety of stamps: pictures, text, labels, fillers etc.
Here's another example, again using Cat's Meow, this time with a seaside theme - my version of a ship in a bottle:
Transparent surfaces can be both difficult to stamp on and to photograph, but it's worth persevering as they give you the opportunity to introduce lots of layers to your work.
Thanks for looking!