I'm looking for a fun & reliable handgun. My budget is about $500~ (give or take $100 if needed) Caliber? 9mm, .357, .40? I want something I can have fun with at the range while bettering my skills, yet has enough stopping power to be used for defense in the event my life is at stake. I don't want a wal-mart special, nor do I want a $1000 collectors item. I've fired several guns in my lifetime, but not enough to know the reliability or other pros and cons of certain handguns. I'd prefer something from one of these companies: Glock, HK, SIG, and Smith & Wesson. Based on looks really. Please give your honest opinion and/or experience with models of the above listed pistols.