Halloween Shamrock Solitaire
Shamrocks is a great little pile based solitaire card game. Unlike La Belle Lucie and Cruel, you can't shift or shuffle cards after you've started a game. Shamrocks gives you a lot of freedom to build the piles up and down, but it has 2 significant restrictions on the piles. You can build a pile up or down without regard to suit, but you can not put more than 3 cards on any given pile. Also, once all the card have been removed from a pile, that pile is gone. You can't start a new pile in it's location with any card.