I've always regretted not going to the Church of the Holy Sepulchre on Orthodox Holy Saturday the spring I was in Jerusalem. If I'd tried harder I'd probably have been able to go, but with the going-out-with-three-people rule that we had, sometimes you couldn't do everything you wanted to. As I recall, the only person who was willing to go with me was my future husband which is quite possibly why I married him later.
The Church of the Holy Sepulchre doesn't really have a good reputation among many Christians, especially Protestants and Mormons, although that of course is a generalization. I've always thought it unfortunate that we so easily dismiss the church because its decoration is so different from ours; or because the people worship differently; or because it's dark and always under construction; or because of political, religious, cultural, and historical reasons, there is often conflict there. It's a complex building that you won't necessarily understand just by going inside once or twice, or if you've already decided it's not for you. Give it a chance.
The traditional event in the church on Orthodox Holy Saturday is the Holy Fire. Patriarchs and archbishops of various denominations sing, pray, and lead processions to the tomb of Christ, which the Greek Orthodox Patriarch enters and soon emerges with 33 candles which are said to have been miraculously lit. The flames from those candles are shared and spread amongst the many people inside the church.
I don't really care where the flame comes from or if it doesn't burn people as some claim, or whatever. I love the symbolism of that light being spread among so many different Christians from all over the world, a flame which represents the Resurrection. That's one of the best symbols out there, I think.