Baseball is my main focus, hands down. That doesn't stop me from looking at some of the other cards available in stores!
Satoru Tsuda is a photographer who takes pictures of cats like you see here. They're fairly funny and the cards aren't expensive. If I find a "box" of these at the right price I might try to put together a set. Finding singles to finish my set isn't easy though!
Kids stickers and cards are usually sold in thin paper envelopes instead of packs, which are torn from the display. Many of them come one per pack, though the Disney stickers are a notable exception with two stickers in each envelope. In addition to anime, cartoons, and photos, there are a few games and pop idol sets (AKB48 being the most notable). They are found in traditional-style candy/snack/toy stores that I frequently see in malls, plus in other stores with similar goods. They aren't really found in large markets that often.