If you grew up during the 80's and 90's, you may have collected these along with similar sticker sets featuring popular animated TV shows and films.I had thought that Panini was long gone, but according to their current website, they seem to be prospering in Europe and many other countries rather than North America like they used to.
http://www.paninionline.com/collectibles/institutional/bt/uk/faq.asp
Being a cartoon nut, I collected many of these sets because it was a unique way to own screen-shots of your favorite cartoon characters. I may still have some collections packed away somewhere and maybe I'll share some examples in the future.
If memory serves me, I collected album sets featuring the Looney Tunes, Tiny Toon Adventures, Darkwing Duck, Roger Rabbit, The Transformers, Garfield, Ghostbusters, Slimer!, Alf, The California Raisins, etc..etc...
Also I remember during the 80's, Panini was trying something creative with their sticker albums by providing 3D glasses with illustrations that would animate when you closed one eye and switched between blinks. That little trick taught me simple animation techniques for sure.
And yes, I actually owned the I Love Snoopy album at one point. LOL