You should definately go with Dead Space and Mass Effect imo. I thought both of those games to be extrememly interesting and fun. Mass Effect had a great storyline and plus the 2nd one will be coming out in the near future. Dead Space was a great horror/sci-fi and kept you on the edge of your seat. Only downfall with Dead Space is the campaign time. Kinda short like 6-10 hours depending on difficulty. Mass Effect varies depending on if you do all the side quests or just stick to the main plot.