There's simply no describing the inner-feelings of looking up to see the Acropolis from afar in the city...or in standing on the hallowed grounds with 2000+-year old ruins at your fingertips. For myself, no where else in the world has history been so soul-stirring than from experiencing the Acropolis, Parthenon, and their surrounding areas. After seeing pictures of these in textbooks all one's life, it's why I say coming here is worth cost of the place ticket...even if you did NOTHING else!
Depending on the day/season, the Acropolis opens no later than 8:30 a.m. and I recommend arriving as early as possible to enjoy your own reverant solitude paying uninterrupted homeage to the place (not to meniton phot ops) before mass invasion from tourist buses unloading. Be prepared to lose yourself in time. I spent over 4 hours my first visit; almost 3 the second. Admission was 2000 drachmas.
The Parthenon is mind-boggling in its present form...not to mention trying to imagine its passed granduer. Most intriguing were the reddish-pink stone steps which led up to the entrance of the temple. They're in amazingly decent shape; polished smooth from footsteps of countless people over the last two milleniums and more. The Parthenon is roped of to keep you from actually walking thru the temple, but I couldn't guess how many times I circled the area with head tilted back, mouth agape. Being here was definitely one of my best, overall travel experiences.
Looking out across the city from the Acropolis was the other major highlight one can loose endless time with just as Socrates and others before me likely have. It's also a good distraction once the place fills up with people.
I found the second visit necessary/needed for giving fuller attention to the lesser temples as well as revisting favorites. Binoculars would come in handy for viewing the Porch of the Caryatids as well for looking down into the Greek theaters of Herodes Atticus and Dionysus; the latter of which was under renovations in '99. Also don't leave the area without visitng the Museum which has many fragmented works from the Acropolis, Parthenon and four of the original caryatids...(Yes, the ones on the temple are replacements!)
Another important area easily missed outside the complex down from ticketcounters is Areopogas Hill where Greek officials used to convene court on these rocks looking up to the Acropolis and down to the Ancient Agora. It's also where the Apostle Paul proclaimed Christ to Greeks as their "unknown God" as described in Acts chapter 17. Because of those efforts, Dionysius was converted and today is Greece's patron Christian saint.