Good question since this way allows steady improvement of programming skills :)
But much depends on your current level. There are tons of games which could be played in console.
People usually start with "Guess the number" and "Stone-Paper-Scissors" - by the way the latter could be programmed quite complex, to try discover correlations in opponent's sequential choices and predict his behavior.
Then many variants of maze-like games follow. Also games with initially empty field where at each move new obstacles arose and player should travel through.
Game "Fox and Geese" could be implemented with simplistic strategy for the fox.
As a matter of fact any kind of strategic board games could be implemented, including checkers and chess - though it requires some advanced level.
By the way there was such category as "text quests" and one of the first games http://en.wikipedia.org/wiki/Colossal_Cave_Adventure
was a real hit - you still can find it somewhere and play... it is cool enough :)