For a while I've been using a set of cheap Sony speakers that my parents handed down to me when they upgraded their whole system. Being a poor college student I can't really afford a high-end (or even mid-range, to be honest) system, but I'd like to get rid of these Sonys since they sound absolutely horrible. I've already upgraded the receiver to a Harman Kardon AVR125 since I needed the coax, optical, and s-video inputs. I wasn't planning on replacing the speakers anytime soon, but... ...last week some relatives bought me a pair of Polk R20 bookshelf speakers as a present. I realize these aren't amazing speakers, but the increase in sound quality is unbelievable over the Sonys (I'm using the R20s as my front speakers right now) and now I want to upgrade my whole system. I can't do it all at once, but I'd like some advice on what I should do first. Right now I want to keep the R20s and the AVR125 and I'm thinking of picking up a center channel speaker next and eventually getting some floorstanding speakers for the front channel and using the R20s for surround. Does this sound like a good idea? Or should I wait and save for the floorstanding speakers first and get the center speaker last? Any advice on what speakers I should look into to compliment the R20s? And keep in mind that I'm on a pretty limited budget. Thanks in advance!