It depends on the job. I'm hiring web devs at the moment so cool functioning sites are great(but rare). I'm certain a few little games I wrote in javascript(b

It depends on the job. I'm hiring web devs at the moment so cool functioning sites are great(but rare). I'm certain a few little games I wrote in javascript(blackjack, and copies of a few of the games from kde games) got me my first job in web development. The CTO loved the blackjack game in particular. I guess the best advice would just be anything interesting that shows off your skills.