A petzy collection of my favourite kind of puzzle, nonograms! Nonograms (also known as Picross or Hanjie depending on where you might've heard of them) are number-based puzzles, where you fill in a grid sheet based on the numbers listed for each row and column. This website has a good introduction and indepth tutorial for anyone unfamiliar.
14 x 15
Reveal Answer
13 x 15
Reveal Answer
14 x 10
Reveal Answer