Lindos is great. St. Paul's Bay was my favorite, closely followed by the Captain's House (bar/historical site) located in the heart of Lindos.
We only went into town after 4pm, and missed the crazy crowds that come for the day as part of packaged tours. I like the time of year that we visited, mid-June. It wasn't too hot outside, but hot enough to enjoy swimming.
I thought the Acropolis was a great setting, but the Italians did a terrible job restoring it.....very sad to see the bad replications that they have done in comparrison to the Acropolis at Athens or the buildings in Ephesus or Rome.
I would recommend spending a night or two in Rhodes Town as well, and also renting a car when on the island.