I picked up Pegs in the Park at a yard sale last week for just $1 and it has fast become a family favorite. According to the box it's recommended for ages 4-8, but my two year old can play with just a little help!
It's an excellent game for counting. But, the thing I really love is that one round of the game takes about ten minutes, which is perfect for keeping the attention of my 5 year old. She tends to loose focus on longer games and ends up in tears. This was definitely a dollar well spent!