I don't know if other people do this, but I really just refer to the Potter books as HP1 and so on. I know the fan community has SS and PoA for short cuts, but really. It always takes me a minute to decipher the acronym. I never have trouble remember the order. :-)
Anyway Harry Potter and the Sorcerer's Stone. This book is truly not new to me. I've read it at least ten times starting from January of my freshman year of college (2001 for future biographers). I was hesitant to start reading the series, but my roommate convinced me and we've shared a love ever since. And I've probably read the series at least once a year since then. I always read in order, except for with movie 6 came out I just read that book because I started too late to do the series. :-) Then I went back and filled in. But what that means is that I've read HP1 like 10 times, but I've only read HP7 3. So there's a different level of familiarity with each text.
However, I always enjoy diving into Rowling's first work. I do like see her writing a little rough. (Come on! You know it is. Every writer is allowed to improve.) I like seeing the framework she's laid for the series and the little hints she's left. John Granger, of HogwartsProfessor.com, suggests that we look at the books as matched sets going into the middle (1&7, 2&6, 3&5, 4 as the crossover point). So I appreciate testing that theory out as I read through the series.
One final thought on HP1, I can't help but comparing movie and book plotlines. I will almost always think the book was better. (The Time Traveler's Wife might be the only exception, and those two come in at a tie.) But my favorite thing about the movies was how they gave greater detail to the picture in my head. I can imagine what the line of poisons looked liked more clearly, even though they cut that scene, because of the dramatic chess scene and the fight with Quirrell before and after that missing part. I do wish they'd release a true-to-the-book version of the movies, but I'm grateful for what we have.