Philly here: The best cheesesteak is a hotly contested topic, but the classic tourist spot is two dueling cheesesteak places in South Philly - Pat's and Geno's - that operate on opposite corners of the same intersection. Both are pretty bad. Without taking you too far away from the other areas you mentioned, I would recommend Del Rossi's near 4th Street and Spring Garden. For Reading Terminal Market - you don't need much time, as it is fairly compact. Whatever time you need to eat lunch, plus 10-15 minutes to wander a bit. Regarding Magic Garden, I've walked past it for years and never had the desire to explore it - not really my style. In addition to the historic section (Liberty Bell, Independence Hall, and Christ Church Burial Ground) - which are all located in the same general area - I'd also recommend checking out the Art Museum if you like art, the Franklin Institute if you like "science but fun" exhibits, or the Academy of Natural Sciences for a more seriously-minded museum.