I went a few years ago with a friend, and as it was her 'special' birthday, we decided to do it in style and opted for the best seats in the house (Poltronissime), where the Italian men wear their tuxedos and the ladies wear long evening dresses.
Before entering the Arena di Verona, it is a good idea to eat at one of the many restaurants in the small streets that surround the Amphitheatre. This way, you can really make the most of the charged atmosphere, whilst doing some serious people watching at the same time. There are lots of gorgeous, designer shops for you to feast your eyes on (I particularly remember the Louis Vuitton shop, which was immediately opposite the ancient Arena).
Once inside the Arena, be prepared to be blown away by the sheer scale and magnificence of it all. The Arena sits 20,000 people, from the best seats on the floor of the Arena, right up to the unreserved places on the upper (very upper!) stone galleries, where you are perched high on the topmost ramparts of the original Stadium, which was built in 30 AD.
When one thinks of opera, the Royal Opera House at Covent Garden, the Sydney Opera House, and La Scala all spring readily to mind, but you will find that Verona combines a quite unique setting with productions and performances of a consistently high standard. Where else could you be watching, on a hot Summer's evening, a performance of Aida, as I was, when at the start of the second act, immediately behind the stage, a huge, full moon rose majestically above the ancient stone walls, and literally hung in the dark sky, surrounded by glittering stars, for the remainder of the performance!
The Italians really do have a love and flair for the dramatic performance, and they are a very demanding audience, which seems to bring out the best in performers and musicians alike. When the audience is appreciative of a certain Aria, they will stamp their feet, cheer and clap, so that, even though the performers are in the middle of an Act, they will perform the Aria again, to even more spontaneous applause!
It really was a magical experience, and one that I will never forget.