As long as you live with your parents, it will never be a "Bachelors Shag Pad." Move out ASAP.
As for items: Get some bamboo plants (or any other house plants for that matter), a bookshelf full of books, a desk, an instrument of some sort, a flatscreen TV, some awesome video games (a Wii or Xbox Kinect (great chance for kino and provide great emotion, laughter and fun), or a Nintendo 64 (everyone loves the old school 64!)), an entertainment system, surround sound, air freshener, lava lamp, Christmas lights, a comfy bed (a queen size pillow top will do just fine
), some smooth sheets, a teddy bear, a lamp, a futon, some awesome artwork, a cool rug, a sweet collection of some sort, sport stuff on display (say you box, have your boxing gloves sitting out somewhere in your room, instant DHV), a stylin' coffee table, a rack to hang your pots from (to show you like to cook, girls love that), a coffee maker.... I think I'm finally out of ideas lol
But most important, KEEP IT CLEAN!! Nothing turns a girl off more than a dirty, cluttered, stanky ass room!