We don't know much about Star Wars Episode 7, but we can safely assume one thing: it won't be set in spaceships and space stations alone. Eventually someone's going to put some boots on the ground. That ground could easily be planets already found in Star Wars books, comics, games, etc., otherwise known as the Expanded Universe (EU). True EU is considered canon, though subordinate to film canon, and essentially has Lucas's thumbs up. Coruscant is perhaps the best example of the influence of EU on the films. Lucas had some basic ideas about it, but it was first realized in books and only later used in the prequels (and in Episode 6 via some "re-imagining"). So the heavy lifting in planet creation has already been done by EU writers, so why not use these fan-approved planets instead of creating the next Tatooine from scratch? And the thought of Episode 7 just recycling past movie planets is nearly unbearable. I could go my whole life without seeing Naboo again and die a happy man. Assuming Abrams and company are cool with dipping their pen in the EU inkwell, here's our choices for 5 planets they must visit from the Expanded Universe.
Dantooine is one of those planets often mentioned in the original films, but we've never seen it in a live-action movie. It was the original Rebel Alliance base before they moved to Ewok-ville (Yavin IV), and it was inches away from being the first test of the Death Star (Alderaan took its place). It's also been extensively used in the Expanded Universe, sometimes just as a stopping point or pit stop. It's a farming community on a planetary scale, essentially, and would make a nice home for the farmboy Luke. It's past as a Rebel base also means it could be used as a future base for completely expelling the Empire's remnants, if that's the plot for the new trilogy. It was also home to a Jedi enclave, or training facility, and would again be an easy choice for Luke putting down roots.