Corcovado, and its sculpted Jesus, is perhaps the most recognizable image of Rio de Janiero. For this reason, I hesitated to go both times I was in Rio, wanting to do something a little more off the beaten path. However, the second time I was in Rio the Sugarloaf was closed because they were repairing the tram, so Corcovado it was.
I went alone, and this was no problem. I took a cab to the base of the mountain, and then took the train up. The train is the second-steepest train in the world, and I recommend it over the drive (it's also cheaper as parking is expensive up there). It runs through Tijuca National Park. It's the largest urban forest in the world (hence the striking green hills rising up from the beach that I saw from the plane).
The crowd at Corcovado was mostly families and tourists; there were a few youth groups on pilgrimage, too. I found the vendors selling souveniers to be unsavory.
All that aside, the view is a splendor (not as inspiring as when you see the coast from an airplace, but still worth the trip). You can see all the way up past Ipanema to Barra da Tijuca, and all the way out through Guanabara Bay. On a clear day, it is dazzling! I could have leaned against the wall for hours watching the noiseless traffic, the tissue-paper waves, and the purposeful migration of the clouds.
The Jesus (a.k.a. Christ the Redeemer), on the other hand, really creeped me out. It seemed such a heavy-handed symbol, and his features are rough-hewn when seen from up close. From the back, you can say a prayer in a small shrine cut into the pedestal. If you are religious, this would be an important pilgrimage site, though.
You can get the train at: Rua Cosme Velho 513, Cosme Velho, Rio de Janeiro. The tel is 2558 1329, and check this website for more info.